There are many types of triggers a user can employ to activate a Keyboard Maestro trigger. Would it be possible to generate a PopClip extension for Keyboard Maestro that takes the highlighted text and passes it as an input (or merely copies it to the clipboard for Keyboard Maestro to then pull itself) to a URL triggered macro.
Objective: Keyboard Maestro extension
User settings:
(1) URL of the macro
(2) Optional setting to pass selected text as input