Hello, do you still own these products? The FBV MK II is designed to work with many different amps, as well as controlling software. That said, some of the buttons relevance will vary depending on what device the FBV is connected to. The FBV MK II functions as follows when used with the Flextone III series amp:
Function 1 - Press & hold for a few seconds to SAVE your current settings
Function 2 - This button is NA (does nothing) with Flextone 3 series (I can think of a million things I wish it would do!)
Stomp - This button toggles the Compressor on/off, whatever you have it set at on the amp.
The volume pedal is always "active" and there is a toe switch (press volume pedal hard with your toe) to toggle between WAH and VOL function. I believe this pedal can be SAVED in whatever state you currently have it set at. At least I thought that was the case. I should double check that myself...