You are talking about 1 macro doing more than 1 action at a given time? I also thought about this, but I think it's impossible because of how MacroDroid macros works.
You have vertical set of actions with or without constraints that are executing from up to down until they reach the end. You can't be at 2 positions on that list at 1 time.
Or can you? Maybe if some actions are already executing and another triggers get fired there can be happening same macro 2 times in 1 time. One part is already executing and one just started. Or 3 times. I don't know.