Don't know if that user is super active on the forum anymore so I'll chime in here - This should be possible, but I think setting up the conditionals will be the tricky part.
The looper's state only gives you updates when the action takes place. You would need to check that the looper is recording and that you sent the proper MIDI message to the Looper - BUT when MIDI mapping, that removes the MIDI message from being passed to the script, so you are in a bit of a pickle. You could make a duplicate 'dummy' modline that passed a similar MIDI message that it used for mapping into the script, but that seems convoluted.
I actually think that M4L would be the way to go for your particular situation. It's easier to combine the API with standard MIDI mapping there then in a script, especially if the conditionals depend on messages from both of those worlds (state of looper, and most recent MIDI message received).
Bottom line, Live's Looper is not great for dynamic and robust LED feedback. That's why I make my own