Thanks, Rich!
I appreciate it’s not trivial to embed debugging support in the add-on and fully agree the questions you raised need a thought-out answer.
Personally, I would say that if by default only rules with active breakpoints would be considered for debugging, it should be sufficient for most cases.
In any case I’ve created an issue as suggested: [jsscripting] Debugging Support · Issue #17415 · openhab/openhab-addons · GitHub