Resident UI complainer activated! Commencing UI post!
Totally agree with #1. Especially FC users probably don't care too much about the main Home screen because you can see what is going on from the FC.
#2 is something that was requested right after the feature came out. The big issue with performance pages is that it's so limited. 10 preset and 10 global params is not enough by a long shot for "quick access to my most tweaked params" for anything but bare-bones live use.
#3 That would be nice. I originally had the idea for this feature (as hold functions) because the labels on the A-E knobs lined up with Amp, Boost, Cab, Delay and rEverb so well, but being able to select your preferred functions on a per-preset basis would be dope. For some reason the Axe-Fx 3 I think has never gotten the "Hold tempo for Tuner" function the floor units have. I like the idea of "hold knob for bypass" for those blocks too.
#4 Color coding would probably be best.
I think a better way to do this would be a "Manual modifier Performance" page. There's only 5 manual modifiers atm, but expanding it to at least 10 like the Performance pages would work.
The modifier system is already suited for limiting the range, but the problem with the whole modifier system is that there's no proper overall view on what exactly is mapped where. There's also no way to toggle them on/off without removing them, and the way the modifiers are blocking any other value source. So when you map a modifier, it can only be controlled by that modifier and not a "last source in" method that would make more sense. This blocks Axe-Edit and the front panel's normal UI from adjusting params with modifiers attached which is just terrible. It is understandable for LFOs and such automated params, but not for manually adjusted things.
Axe-Fx 3 has absolutely no issue with the "last source in" functionality as long as this is done via MIDI Sysex like Axe-Edit does. Fractal just doesn't provide any documentation for current gen, and the last gen Sysex docs don't apply. So it requires reverse engineering, building your own middleman software and figuring out all the parameters. A lot of work.