In Belgium and France, there is a slow move upwards, mainly for large sizes. The 30mm in my opinion is slowly dying there, perhaps not in Germany.
Attraction is seen on EBay sales, where Germany issues many many flats constanttly (2)3,000) for 400 in France, much less in the UK, and almost one elsewhere How do you call them in the USA ?? perhaps I have not the correct search word) In France "plat d'étain" in Germany "flachfiguren".
In the Européan competiions, a growing number of flats are presented since 3 years.... requiring more and more competition to issue a separate category, sometmes two (fantasy and historical).
Also see more in the European french FFigurines trimestriel magazines...