@airtex2019 You are THE MAN. Thank you.
I added
set g_nButtonsPerDevice 32
set g_nHotasPinkyShiftMagnitude 256
to the Falcon BMS User.cfg (additionally to the stuff required but already written in the keyfile “readme” regarding POV), made sure that the Stick was on top in the DeviceSorting.text and started BMS using the “Legacy” Launcher and reloaded the Keyfile.
Seems that all keys were assigned properly.