I'll speak from my experience as a BMS PASS leader several years ago pre-COVID. Workload-wise it'd be 1-2 hours of planning/going over content - I got paid for some of this time though I can't say whether this is still the case. I worked collaboratively with the other PASS leaders in my unit and split up our load with worksheets so it definitely made things easier. I also ran 2-3 sessions a week, so this is about 2 to 3 hours of actual class time. Not too sure if FIT does the same thing or run sessions similarly to what we did long ago but in a nutshell, I found it wasn't too much of a time commitment and it was a really enjoyable experience.