I just can't imagine what could be better, sonically.
I’m fairly happy with the sound from my FM3, and of nothing ever changed from where things are right now, I wouldn’t mind at all (with them VC being one notable exception, this one had a long way to go to become great). And just mere computing power will make things even better as more blocks with higher settings can be accommodated.
But there are a ton of things that need attention and love as right now they are in mediocre to outright bad state:
1. The headphone amps on all Fractal devices need to have proper output impedance, and ideally a separate level control independent of output 1
2. MIDI capabilities in current gen are a downgrade from even previous generation in many respects, these devices can’t send MIDI over USB (FM3 doesn’t even have MIDI over USB capability - what the…, it’s 2025, come on), and of course having just 6 control switches to send MIDI is kinda ridiculous. And even where there is a possibility to control things over MIDI it’s quite limiting in that if you assign an external controller to a parameter you can’t change that parameter manually anymore. That’s like a blast from the last century stuff. So the whole MIDI interaction with external devices and software needs a real overhaul, IMO.
3. Footswitch layouts and views are great but also deserve a lot of improvements as some limitations are weird, like why in the world can I have a stand-in switch assigned to just one layout?? More than one function per switch would also be very useful, as well as assigning MIDI message send to any switch, etc.
4. A large color display is nice but it can certainly do more in a performance mode than just be an active scene indicator.
5. The whole setlist/song functionality needs a lot of enhancements. Why 6 song sections? Songs should have parameters like tempo, midi messages, they should be selectable via midi etc etc etc.
I’d definitely love to have an onboard mic preamp, although I know a lot of people object to this. But the rest is more or less hygiene type of stuff, just foundational functionality for a modern device, IMO.