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There are less members using ISO layouts, and even more separation between all the ISO variants.
French ISO is quite popular, although there was another layout that the French government was promoting, if I remember correctly (which might not be the case). BÉPO perhaps?
German ISO is also quite popular, especially with Cherry being German-made.
Things have improved considerably over the past few years though, at least ISO is considered for most group buys.
The best thing you can do if you find a group buy you would like to join is make your voice heard and vote for French ISO add-on! Also see if you can encourage a few other French members to do likewise - even if they commit to buying just the ISO add-on, it might push numbers up enough for it to be included in the set.
I've heard that some ISO RealForce keyboards actually have a PBT space bar, which is great! Maybe use it for a while and see if the space bar starts to get shiny. If so, it is ABS.