Personally I'd really like to see more historically accurate period clothing.

Sets along these lines are good. Renapd's Napoleonic sets are excellent I think, for example.

Some more First World War military, medical staff and civilian clothing would be useful.

Some more 1940s, 50s and 60s everyday civilian clothing would be great.

Sets that have clothes for the whole family, e.g. V4, M4 and K4, would be fantastic.

Period sets that have outfits for role stereotypes would be great; e.g. 1950s Policeman, Banker, Housewife, Workman, Doctor, Nurse, Schoolteacher.

I'd imagine a lot of this variation could be achieved with morphs and mats for a core set of cleverly constructed clothing figures perhaps?

Just throwing some ideas into the mix here... perhaps others will agree on some of them, in which case it would likely be worth someone's time to make these for the market I guess?

Overall, quality and attention to detail is all important really, I'd say, for these sorts of items.

They may well just not be worth a commercial vendor's time to undertake?

On the other hand they may well be, but just on the basis of paying a smaller dividend over a longer timeframe?

Cheers