There's also an option Show assignable controls, but is very difficult to find!
The documentation seems old, but if I pick the Display menu on the left panel,
- Display/>Module Option/>FX/>Show Assignable controls -
I can then see, ONLY in the left panel, the selected effect with a list of parameters, than I can right click and Remote Control.
Thanks anyway, I finally give up TH3 and bougth hardware with pedal for my amplified guitar.