Fwiw, I'm afraid I'll timbuck out on this thing. There's just too many things that would require workarounds. Some of them actually making me wonder why it's like that.
The main showstopper most certainly being the switching options. They're just not great. You are at the mercy of what FAS is offering and that involves a lot of dual-switch or hold-press actions. I don't want that live.
No way to freely configure any switches but external ones - which don't give you visual feedback. Let alone that ideally I wanted a wah/vol pedal, which would already need both external inputs.
All of my potential issues could easily be solved in case I could configure the switches freely, but that's not a thing. It's actually baffling because this is a unit coming from a company also offering some of the most complexed foot switching options there are in their other offerings. But on the AM4 they decided to completely dumb them down.
Another thing that would require a workaround is not being able to send an independent volume locked signal the FOH way while still being able to control my monitor volume. I would need an extra split/DI box and an extra level control to get there. Nothing I wanted from an all-in-one unit.
Then - and I actually didn't even think about it until a little earler on (maybe I just had it engraved in my memory that this would be a standard anyway): There's no looper. While I'm not using loopers for live purposes too often (well, in fact, I do with a little bass/git duo), I do very regularly use them to kill some time. And ever since 2010 (or so), when I got an M13, each and every of my setups had a looper. Not having one available is a pretty noticeable drawback. Let alone I sometimes use pre-everything loopers to adjust tones, which is an incredibly great thing.
Further, there's no global EQ. Now, these days I very rarely need them, but whenever I feel like reaching for them, it's for very good reasons (most typically when playing through bad rental wedges).
And while I don't want to get into this yet again, just for sake of completeness: The lack of a programmable insert point doesn't help, either.
All of these (but maybe the programmable loop) are things I expect from a modeler in that price range released today. In a nutshell, featurewise (note: not soundwise) this thing is as rudimentary as it gets. It's almost as if if wasn't made to be used as an all-in-one unit. Which it possibly indeed isn't. But it could easily be because adding most of the mentioned things wouldn't cost FAS a dime.