To give some insight into the 'custom' foot switch configuration options of the AM4, I'll paste the message that I posted on the FAS forum.
On both the AM4 and VP4, 'Gig Mode' is the default 'press & hold' configuration, which is awesome.
If you prefer a personalized approach, without two-switch combos, that's also possible.
Here's how I run the combo of AM4+VP4.
Guitar goes into VP4.
The main preset has:
1- Volume for automatic volume swells
2- Wah, set to Auto-Engage, using the EV-5 pedal on the left
3- Tremolo
4- Rotary
Those are the single tap functions. The "press & hold" functions of the same switches are:
1- Mode Select, to enter Preset or Effect or Tuner mode
2- Channel Picker: to choose between 4 channels. Not used with Wah, but for other presets
3- Channel Picker: to choose between 4 types of tremolo
4- Channel Picker: to choose between slow, fast and 'break' rotary
After careful selection, I have only 3 "effects" presets on my VP4: A1, A2 and A3.
A1 is described above.
A2 has Pitch (Whammy), Phaser, Flanger and Chorus. The Whammy is 'activated' (Mix jumps from 0 to 10) when moving the pedal.
A3 has Plex Delay, Multitap Delay and more. The delay blocks that I want to be ready for channel switching, are located in slots 2, 3 and 4 of the preset.
So if I'm in preset A1 and decide I want to use the Whammy, I press & hold switch 1, select Mode Select, select preset A2 and immediately kick on the pedal for the Whammy. And vice versa. Note that switching presets is gapless, so the sound doesn't change when I go from A1 to A2 on the VP4.
The custom 'press & hold' functions work global, so they also apply to presets A2 and A3.
Meaning that I can access Mode Select, and switch channels of blocks 2, 3 and 4 in that preset.
Signal goes to the AM4 through SPDIF.
On the AM4 I stick to a single preset.
It has two Drive blocks, the Amp block and Reverb/Delay block.
The Reverb/Delay output is stereo and uses the trick described above with Echo Reverb types and the 2nd EV-5 pedal.
The "press & hold" functions of the switches are:
1- Channel Picker: to choose between 4 types of drives
2- Channel Picker: to choose between 4 more types of drives
3- Amp Mode: to have access to the amp controls and the 4 amp channels with my favorite models
4- Channel Picker: to choose between 4 types of "Echo" reverbs, including one with pitch shifting (shimmer)
The switching takes some getting used to, but it soon feels natural.
I currently don't use Scenes. If I did, it would probably be for something like pre-configured "Solo" or "Wet Auto-Swell" and stuff.