To the OP's point, the Axe-Fx rack has four perfectly useable knobs on the front panel, but they don't change any block parameters when in recall mode (on a preset, no editing) which is the cause of a solvable problem.
*edit* Someone posted there is a mapping function - it requires per-preset mapping, so 80 individual mapping maneuvers if you have 20 presets. That jolted my memory. I tried this, and if I recall correctly, the screen doesn't change to indicate the parameter you're changing or by how much, and you have to go through a save maneuver, which is why I now remember abandoning this approach.
Maybe it's too complicated to implement, but if users could map one parameter from any block to each of the 4 front panel knobs life would be so much easier, and this might be a more user-friendly implementation.
- Activate/move a front panel knob, the unit goes into edit mode for the amp, cab, drive, etc mapped to the knob, goes to the parameter mapped to the knob, and the display changes to spell the block, the parameter and a big number for the value. This is similar to RAC12 implementation.
- Move the knob the knob a second time, either way, and it begins changing the value of the assigned parameter accordingly
- The parameters autosave in 10 seconds unless the user presses "exit"
- Done, Done and Done
- In any other mode except preset/recall, knob mapping is superseded by normal functionality
Turning the 4 knobs in this mode wouldn't be global. It wouldn't change those parameters across all blocks, just the block(s) in the preset you're playing.
If you happen to NOT have that block or specific "knob" in your preset, the front panel knob is inactive. This encourages mapping of your most-tweaked, mission-critical parameters.
Having a fast tweak like this available is very desirable for gigging. All you need to do is watch Jeff Beck or Jaco Pastorius or others to see the usefulness of a 2-second, mid-song tweak. Plus it makes the unit much more user-friendly at the gig or in the studio.
Honestly, after seeing the RAC12 implementation, I'm surprised Fractal didn't implement something similar.