You can assign the aux switches to behave as the footswitches do (almost) as described on page 32 of the User Guide.
"Almost" refers to the fact that the Aux Switches are momentary-closure switches and so 'press and hold' isn't possible. On the unit pressing and holding the right footswitch toggles modes between Play and Bank. To accomplish this with an Aux Switch requires assigning one of the switches to this toggle function and, as a result, if you need all of Bank and Play features, you're out of luck.
If you need remote control of some Play and some Bank functions, you can arrange that. For example, one Aux Switch could be assigned to toggle between Play and Bank Mode and the other two Aux Switches can then be assigned to behave as the footswitches do in each mode,
