@la szum
I have thought about your words and advice some more and I think you are right.
A few months back, the last time I used the FM3 through studio monitors, the joy of the stereo field with IRs did make up for the loss of the Amp where I'm at that I was looking for, but have only had in mono when playing through my cabs. And I did manage to find some IRs that worked and I enjoyed enough to stop wanting to enter the rabbithole again. I have some YA IRs too.
Yeah those Neumann monitors are pretty decent and stupidly flat. (Class A/B too!).
So perhaps I should simply enjoy both amplification approaches for what they are and not try to force it.
I don't gig at the moment and probably never will again (See the Gig Trainwrecks thread!). I have felt guilty about owning the Bella + some amazingly good pedals, as well as owning one of the best modellers on the planet. Was hoping to rationalize and downsize to just one solution (to rule them all). The FM3 isn't so great with the Bella - it's okay, but the pedalboard is better with the Bella, and the FM3 is better on its own.
I also wanted to reduce my wiring and complexity of the pedalboard... But I only have a small number of carefully curated pedals anyway, so it just doesn't matter so much, I guess. The floor in our music room looks way busier and messier because I have both rigs in one spot and I keep changing things about with everything in flux. And it's not just my gear / rig in that room... haha.
I'm not in any sort of financial mess at the moment, so I could always enjoy the Bella for another year and don't have to sell now, anyway.
So this thread is pointing to some conclusions in other similar threads where people have said "Why not both?".