The TAP footswitch on the H9 only has two modes, preset search mode and TAP tempo. No other function can be assigned to it. It is possible, nonetheless, to use a single, double, or triple auxiliary footswitch and connect it to the EXP input of the H9 for the purpose you seek. You may assign the “performance switch” to any aux switch of your choosing; the performance switch is what controls “slow/fast” on the Rotary algorithm or things like “repeat” on delays, etc. You can even have an expression pedal and an aux switch at the same time on the H9 as long as the EXP input is set to “both” and you are using a single switch along with a TS expression pedal; TRS expression pedals DO NOT work in this mode.