and a "setlist view" would be also a nice thing to have, I mean a screen where you can just see your set list nice and clear.
Yeah. And, talking about this: What about having an additional "volume offset" per patch, available straight in that setlist manager?
It'd be nothing else but an additional volume knob tied to the setlist, not altering the patch you're using, also only in effect once you call up the setlist. No need to save that setting, either, it'd automatically be part of the setlist.
Thing is, once you're using plenty of different patches (I typically don't, but I most defenitely would in, say, a theater situation, in a regular band playing original stuff, etc, some cover band folks do as well), balancing their volumes against each other can become quite tedious. Also, you may want to use the same patch just with a different level in more songs. Having to go through each patch and perhaps even resaving it (as long as global blocks aren't a thing) is quite laboriuos. A patch volume offset tied to a setlist would nicely adress that as you could see all patches at a glance and have immediate access to their volumes just by tapping them.
Now, before anyone mentions it: I am perfectly aware that a single volume offset wouldn't do the semi-modular nature of the HX stuff justice. So, in case you were running, say, multiple sources through the unit, it possibly wouldn't work anymore.
But my guess would be that in 95% of all cases this isn't relevant and the overall patch volume would be set by a single final output block. So in all these cases, the scenario described above would work.