Awesome, I was completely clueless with that FH5 issue!
I've made a few tweaks if you don't mind looking at it and updating the MR: https://gitlab.winehq.org/rbernon/wine/-/commits/mr/1535-tweaks
More specifically I added a test for the initially modified parameters fix and it looks like the envelope report is supposed to be sent too. So I changed the fix to simply consider that all effect parameters are initially modified, and send the envelope only if it was also specified.
I also then reordered the commits a bit and tweaked the axis mapping logic, so that it's done within the async operation and while holding the effect critical section to serialize concurrent accesses.