Keyboard Maestro doesn’t have an easy way to try macros from within the macro browser window. The only way to test one is to edit, select all the steps, and click the “try” button.
This Applescript simply executes one or more selected macros. If any of the macros are disabled (including if they’re in groups that aren’t enabled due to conditions), they will fail to run.
You can turn this into a Keyboard Maestro macro for hotkey access.
Download: Execute Selected Macros.applescript