Don’t use auto engage for something like this. You want to just increase and decrease parameters without turning the block on and off. This is possible, many do it.So as you know only 1 amp with FM3, anyways I was trying to duplicate the ability to blend from a supper nice rich clean amp tone using the EV1 peddle into a nice overdriven sound and I was quite surprised that the FM3 was a complete fail, I experimented with about 8 different marshal types adding a modifier on the Input drive and to my dismay discovered this is supper f-n lame as it turns the amp block on and off in order to engage the EV1 peddle, Ug.. Then I tried to use a drive block in a similar fashion but just not that graceful when it kicks in and most of the drives do not play well when traversing from that clean sound as I find that most of the drives drop the volume level from clean. another thing I also noticed that the EV1 peddle sometimes misses intermittently. I got to say I use to have a Zoom G9.2tt peddle an it did this much better than the FM3 with 3.01 FW. Id say to you if this is a must deal breaker control to have then the FM3 at least now with current FW is not going to work for you.
But I will say FM3 dose so many other things so well that I never even noticed until I read your post and experimented.
Cheers
Also, decreasing gain does decrease volume as well. You’d need to put a Level control on the same pedal that works in reverse - turn gain down level up, turn gain up level down.
This is definitely possible.