THIS page from the CSV folks. It calculates that the pump will run 9 minutes at a time followed by 36 minutes of off time and it will do that 32 times a day if I leave the low flow stuff going all the time. Plenty enough time for pump cooling. And this is about the worst case for this design.
But even if the pump does run for 75 minutes at a time, is that really a problem? I don't think I have a problem with cooling flow -- the pump is shrouded so all the water is flowing past the pump. And I don't think I have a problem with minimum pump cooling run time -- 9 minutes should be way more than necessary. Are you worried about the pump overheating? Or bearings wearing out or something?
Perhaps there are real world practical issues that I can't see because I've never done any of this before.