Also, I think ZB+ is going to be a waste of time.
Alright, time for a rational, reasoned defense of ZB+. As I have noticed a disheartening lack of them.
First off, will ZB+ be good? That is the premier question we need to answer. And no, I'm not going to argue "we should get it too see if it is good or not" because that, is a silly argument. The argument will be thus. Historically, we have never gotten to level 2 of an art and said: "wow this was a waste of our time." Arts are designed to be enticing at all levels, for the level that they represent. ZB represents low to mid red, and it is wholly unappealing to late yellows. FSA, on the other hand, is for late red to mid/late yellow, and it is extremely appealing right now. We can't say that we expect an art to be bad when no art has been bad for the level that it is meant to represent. So the argument that we have no idea if ZB+ is going to be good or not is based on a bad analogy to ZB. ZB+ is a better and improved art of ZB, it will be better and it will most likely be appealing to the level that it is meant to be at, which is low yellow to late yellow, probably.
Second off, why do we want ZB+, or, what does ZB+ offer us? First off, it is cheap to learn. We get -10 successes needed to learn it after the first level, and we get an additional =5 to successes to learn it because it is a heart art. This means that it is -15 successes per level after the first one. This means that it is cheaper and easier to learn than any other art we could get (in terms of successes). Next, it offers actual tangible advantages that our other arts don't give us. First off, it's passive stacks with SCS to a ludicrous degree, allowing us to reliably go first (important with our need for FVM) and stacks with FSA to increase the damage we deal with projectiles, or primary damage dealing weapon.
That is just for ZB's passives, which will be improved and possibly expanded upon with ZB+. The techniques are next. Against the Wind provides a unit-wide debuff for the enemy by both lowering the dice they have for offense and defense, while also limiting their speed. We can expect significant increases in this from ZB+. This debuff is useful for A) kiting the enemy, and B) dealing with a bunch of mooks where we want to hit them better also don't want them to hit us. (In contrast to the pure defense that TRF gives us which is for dealing with peer or higher level opponents.) This debuff can be potent and ZB+ is going to make it even more potent.
We then have the support function of ZB. Guiding Zephyr. This provides a buff to all allies in range, as well as increase the damage we deal with projectiles. Again, this is for when we are wanting to deal more damage to the opponent, as well as keep our defenses up. We can expect ZB+ to dramatically increase this as well, to make it more appealing for the area that it is in.
Finally, we have Shielding Gale, which provides protection against projectiles while simultaneously forcibly removing unwanted people from our personal space. We don't want people targeting us in melee, as we have a better defense against ranged projectiles (look at ZB's passives again). This art, which we can expect to be significantly upgraded helps with that. It is also an instant which provides a lot of opportunities for which instant we want to use in a given situation.
Why should we get ZB+ now, rather than later? Every single week we are going to have a lot of stuff to do, especially when we have EPC quests and Sun Liling's quests to worry about. It will always be difficult to find the time to go to the archives and get an art because we will always have things to do. So the real question is, why shouldn't we get it now? We have an action that we can spend on getting it that doesn't take away any of our other opportunities outside of Elder Jiao's training. So the question then becomes, is getting ZB+ now a good use of Elder Jiao's training.
There are a plethora of options available to us for his training. Formations, Investigation, AC, Melee, etc. So what do those things have over ZB+ now that would make it more productive to get ZB+ later? Formations is a huge time sink and if it is something we want to pursue, then we will want to get more actions then Elder Jiao's training to actually bare some fruit. After all, he is not going to be providing us with formations for our use so we have to come with our own. And we don't have any to practice with (unless you want to practice with the two-dot security lock). Investigation runs into the problem of overtraining AM, especially since we want to use AM with the 8fold path pill week. AC runs into that same problem and we don't have the meridians to effectively use it currently. Melee... is a completely different bag of worms that I don't feel like getting into. Suffice to say, melee probably isn't our best bet either.
Other suggestions have been made, but none of them have gained any traction. There is a definite investment to make in any of them and none of them stand out as particularly noteworthy. ZB+ is an option among many, but an option that will yield immediate results. If we approach getting ZB+ as something that is going to wow us, as every other art has that we have acquired when we have acquired them, then there is no particular reason not to use Elder Jiao to get and train in it.