Cavecolor: Another one that's pretty tough for me to think of anything for. Maybe something kind of, like, cave painting related? Darkness, but color? Safety and shelter?
Drawsource: Art supplies, the element! And more broadly, a direct connection between imagination and reality, via the medium of the visual arts. Heavily social focused but with some pretty crazy esoteric potential at the high level.
Closedheat: This gives me the feeling of a sort of glowing aura that sort of 'melts' things, locking them in themselves, limiting mobility and interfering with any sort of functionality.
Pressurepop: Might be a little cliche, but I imagine this as being an exhalation of bubbles. Fairly combat oriented, with bubbles having a pretty potent mix of physical, mental, and esoteric force they release when broken, as well as powering up when the elementalist is at a disadvantage.
Vacuumtradition: A relatively slow going element. Focused on permanent structure of utterdark substance. Making new constructs is excruciating, and gets more difficult with each construct, but constructs also naturally and automatically 'improve' over time, becoming more durable, more effective, more metaphysically real, etc., newer constructs have faster rates of improvement.
Chainsmoke: Obviously an element that's taxing on the body, causing long-term degeneration with even conservative use and addictive to use, but which is otherwise an all-around excellent battlefield control element, with fast moving, durable chains which have the potential to be improved along esoteric dimensions.
Flourishlump: A relatively basic element, a simple mass of muddy stuff, which does not excel in esoteric or complicated uses, but which does have an excellent level of persistence and a truly prodigious rate of production, with the elementalist even being able to fling themselves through the air at extreme speeds simply by directing blasts of the element.
Greenshallow: Another one that I'm really rather at a loss for. Probably something swampish? But I'm not sure how.
Perfecttable: Honestly I selected this one pretty much entirely as a joke. I'm not sure how it'd work seriously.
Pricespread: A defensive/buffing element, taking the form of a sort of paste or slime. It provides some basic damping of attacks it absorbs, but probably more valuable, it lets allies who are covered in it 'spread' the costs of abilities they use, even in ways that are bit weird, such as being able to use a 'once per day' ability once per day per ally by spreading the 'cost' of uses per day between everyone. Potential develops open up even more weird, esoteric ways of splitting things up between allies.
Simulationwind: Not sure exactly how to describe this one in terms of party roles, but the gist of it in my head is that it's a sort of ethereally wind that the elementalist can blow through things to sort of 'read' them, which in turn lets the wind create invisible, selectively-tangible 'simulations' of the thing that was read. Advancements to improve the accuracy of the simulation, number of simultaneous simulations, number of simultaneous read objects, etc.
Velvetprinciple: Another one that I'm pretty lost on. Probably social focused? Might also be highly defensive in terms of physical combat, at the expense of actively weakening the elementalist's physical attacks.
Stickyagent: A minion creating element, I think. The minions are all pretty standardized, and fairly stealth-focused, made of sticky slime, able to compact down into cracks and crevices, stick to the bottoms of people's shoes, crawl along ceilings, etc.
Readypace: An impressively generalist element, basically just a progression system as an element, automatically developing new uses slowly but surely as the elementalists does, anything really.
Jailcrystal: Hunger's soul evocation as an imaginary element, basically. The creation of receptive crystals that can store and hold targets, but with potential advancements to do things like capture qualities of targets, or to target abstract things, etc. Also potentially lets you play pokemon, like Heavenly Tomb.
Cornstage: Already talked about, both by me and others.
Pureconsideration: 100% mental focused element, just straight buffs to mental stats, the ability to create mind-boosting potions, the ability to expand the mind into the substance of the element, granting vastly increased memory, mental speed, etc., but very fragile, subject to physical disruption with potentially catastrophic results if something critical to the elementalist's body's survival had been uploaded to the cloud.
Copybronze: A sort of bronze liquid that can temporarily take the form of things it reflects in its mirror polish. Baseline can only copy physical objects, and will often fail to have unique physical properties of objects it copies, instead behaving like metallic bronze, but advancements can improve the accuracy and allow for the copying of more diverse things, like magical spells or fighting styles.
Ordinarycorruption: A very subversion-focused element, kind of like Conspiracyworm actually. Slow-acting but permanent, slowly overwrites the world in favor of the elementalists, and overwrites the elementalist in favor of their worst self.
Otherslump: Another one that I really have no clue about.
Pauseslip: A sort of time-element, long and thing sheets that can be used to 'store' time, and then used either to trap or slow opponents or burned to accelerate the elementalist. Advancements for more esoteric uses of stored time, like storing the duration of buffs or storing hours spent sleeping. Probably comes with passive, automatic Dodge chances as well.
Farewellmissile: Well, it obviously takes the form of 'missiles', probably ranging from as small as a game dart to as large as an ICBM or maybe even more. Definitely scales with the tech level of the elementalist. Not sure how to include the 'farewell' into it, though. Overall, it might actually be a fairly defensive element? Something like, its attacks are all very strong and potentially with huge AOEs, but that the damage is almost entirely focused on negating other attacks inside the effect, rather than actually damaging opponents.
Properland: Super nation-building focused, I think. The element itself takes the form of a sort of soil, which at once is excellent for growing crops but can also easily be compacted into roads or solid foundations and then erected into buildings and other structures. Permanent, but with little potential for advancement, with the sort of aura the element exudes being mostly fixed, encouraging people to follow their compassion and to cooperate with one another, and calming nature, reducing the severity of storms without decreasing overall rainfall, limiting the aggression of wild animals, discouraging the growth of weeds or destructive plants while encouraging the growth of crops or other helpful plants, etc.
Worldcoat: Another sort of spatial element, I think. I guess bit like a microcosm of the Voyaging Realm actually, in that it lets the elementalist 'steal' patches of space to add to their coat, increasing its internal volume as well as introducing sort of world-elements based on what was absorbed.
Flowerhumor: A sort of pinkish liquid, I think that encourages plant growth wherever it touches, especially of flowering plants. Potential esoteric advancements in the form of encouraging the growth of specific flowers, including ones with their magical abilities.
Utterfeeling: Another one I'm at a loss for. Probably very emotional, but that's kind of obvious.
Doctorspin: A combo healing/insidious element. The element itself takes the form of whirlwinds of healing gas, capable of healing most mundane injuries and with potential advancements to heal more magical injuries, but with the added ability to insert subconscious compulsions, aversions, and other behavior modification into those healed, in proportion to the amount they're healed by.
Causeclimb: Another very progression-y element, I think, though more focused and faster than Readypace. Probably something along the lines of picking a cause or movement to throw yourself into, and gaining fast, powerful progression that degrades quickly if your devotion fades (even if the movement is successful in the end).
Warbrilliance: Mental stats applied to combat is the name of the game for this one, I think. Ridiculous stratagems, light precog, and general utility effects that are all very specifically tuned to aid in a war effort, conveniently packaged in the form of searing white radiance.
Itemorbit: A sort of alchemical element, I think. A liquid that can dissolve objects, which lets them be mixed together and then precipitated out as new fusion of the inputs, or separated and precipitated into purified components.
Tirednail: Offensive/debuffing element, I think, that tends to take the form of malevolent metal spikes that drain away the energy of whatever they pierce, a baseline effecting primarily living things, but with potential advancements adding all sorts of entropic effects.
Empiricaltumble: Another one that I just added because I thought it sounded funny, rather than because I had any idea at all about how it'd work.
Buffetplastic: Fake food for fake benefits! Buffs and debuffs packaged together to let allies make favorable tradeoffs, with potential advancements improving the ratio of buffs to debuffs, expand the range of potential buffs and debuffs, as well as standard stuff like improved output.
Civilroof: A bit like Properland, I imagine that this is a very civilizational element, a sort of aura or atmosphere that falters when used in wide open spaces but can fill up an enclosed space to provide powerful mental and social benefits.