On a Mac one has to configure speaker settings externally using Apple’s Audio/Midi app so that FMOD channels will correctly assign. But that changes all other assignments in other software apps. For example with settings made within Mac’s Audio/Midi program it is no longer possible to audition mono files in the finder.
This a major time consuming pain for Mac users who use a range of audio software for lots of different purposes.
FMOD programmers may not think this is a priority but it is if you’re the end user with lots of other apps to deal with it is a major inconvenience to constantly unpick the routing mess caused by this. I don’t know of any other professional audio program that leaves speaker channel configuration to Audio/Midi.
Otherwise I think FMOD is great.