Can I choose not to output the microphone sound via the BOOTH output?

Yes. The way to do this depends on the DJ software you're using.

■rekordbox for Mac/Windows
See [rekordbox for Mac/Windows] > [Changing the settings in rekordbox for Mac/Windows] in the Instruction Manual.

■rekordbox for iOS/Android
See [rekordbox for iOS/Android] > [Changing the settings in rekordbox for iOS/Android] in the Instruction Manual.

■Serato DJ Pro
See [Changing the settings] > [Utilities mode settings] in the Instruction Manual.

You can read the Instruction Manual [here].