A bit late to this thread but it might help future Google searchers.
I'm an M5 user but it works similar on all M devices. You can select your desired effect, e.g. Analog Echo, tweak the knobs and save your personal settings onto one of the 24 available scenes slots.
You can then back up all your scenes (or just individual scenes) to your PC via MIDI-USB cable. A MIDI software (e.g. freeware like MIDI-OX) can listen to what the M5 sends and store it in a sysex file on your PC.
How you can initiate the dump process is described in the pilot handbook but mind they printed one mistake: The manual says "press and hold Tap while you press down on the model select knob" but it should say, "..press and hold On/Off while you press down on the model select knob."
This sysex file contains all your presets & settings that could theoretically be backed up or shared online to get a specific sound setting from someone else. But as you see it might be faster just to set it manually by visual reference or just by ear. It's not that easy to quickly share your settings and I think that's why M series is not part of the Customtone page.