If you have your Mastermind set to send MIDI clock, MIDI clock will continuously run, broadcasting the tempo at all times. The intent of MIDI clock is for the Mastermind to be the clock master, with the Mastermind always in charge of the tempo. There's another way to do tap tempo, though:

• In MIDI Settings, set MIDI Clock to Off
• Edit your Tap Tempo button, select Add Action, then select your Eventide/Strymon pedal and Tap Tempo
• In the button settings, turn off Send on Preset Change, turn on Update on Preset Change, turn on Flash w/ Tempo, and turn all other checkboxes off.

When it's configured like this, it will only send tempo taps when you're actually tapping the tempo button. Changing presets on your pedal will change the tempo according to each preset on that pedal, the Mastermind will not override that tempo until you tap a new tempo..