Getting a bit fashion history-brained again, even tho I'm far from fashionable
Keeping in mind the more formal morning coat was more frequently used for business by the urban aristos & bougies of Americas & Europe up until WW1, and then replaced with the more casual - but still more formal than suit - now-extinct stroller suit (called the Streseman in IRL interwar Germany)...
We're approaching the era when Sun Yat-Sen adapted Japanese college uniforms for the RoC's longue suit equivalent - the
Zhongshan suit aka the Mao suit with a shirt collar and 4 pockets with more "showy" design than longue/business suits.
There's also the similar
Stalinka with 2 similarly "showy" chest pockets and a shirt collar, which was itself based on the
"French" - a Tsarist Russian military jacket
We could be seeing ourselves switch to something like those three, since I assume in the decade+ after the 2nd Revolution & the Great Eastern War people have freely did the blazer/sport coat + slacks combinations from the (currently) "sporty" longue suits.
(Callback to when the French diplomats & emperor dress in country clothing to casualize themselves during negotiations for the Schnabele crisis since our own side wore the then "sporty" suits)
Maybe we'll wear a similar suit with shirt collars inspired by our military jackets due to how intertwined the civil and military side is since the First Republic. For inspiration,
this Imperial German one in wool and a similar design in cotton drill (akin to cotton chino) for summer could be the basis for post-war office wear. Granted, we use subtler & more drab uniforms than IRL late 19th century/early 20th century uniforms which would likely lack the Imperial German uniform's red piping, brass buttons (wood, ceramic, & iron are potential cheaper but still hardy alternatives), & no epaulets (this "victory/mil-wear/Leute suit" is not intended to be worn by on-duty soldiers, after all).
Perhaps the "going out" version of the mil-wear (Leute-wear? Pls don't laugh) would have the flap waist pockets + "boat" chest pocket configuration standard for the longue suit...
or maybe - as
@C_Z discussed with me elsewhere - veterans of the war would instead input elements like the amount of buttons, the design of the sleeve buttons, & the design of the waist pockets to the longue suit jacket or "odd" jacket (equivalent to IRL sport coats & blazers) ensemble for both office wear and "going out-wear".
For cooler weather,
@C_Z suggested that people could be quick to adopt sweaters & cardigans with
IRL M1911 or similar practical design as an alternative to jackets in milder weather conditions or as a mid-layer under it. I could certainly see us eventually adopting it as socially acceptable for indoor office wear layering and relegating the "mil-wear" suit to outerwear and/or more sober affairs (funerals, legal tribunals, international diplomacy, by civilian officials during central government ceremonies, etc). But I project the mil-wear suit to be used for quite some time after the Great Eastern War due to being more iconic since such sweaters would likely only see use as mid-layers in really deep winter conditions, while our major gains were made outside winter AFAIK (e.g. Vienna & breaking thru the Alps).
On the warmer weather side, we could eventually progress from a cotton drill or linen version of the mil-wear suit as standard office wear to just shirt and slacks after the popularity of the iconic original milsurp trends down. A driving factor that could inspire such a shift could be - through our Spaniard allies - Hispanosphere workwear that later became accepted IRL as alternative smart attires such as the
guayabera/camisa de Yucatan/other names across Central & South America as well as
barong tagalog from the Philippines.
Edit: changing some sentence structures & fixing some writing