On dirt and mud, I already acknowledged that potential pedal and cleat issue above. I don’t ride on wet roads (fair weather rider as mentioned).
Besides, I’ve already dealt with the dirt/mud cleat issue on occasion even with road riding. I’ve had to fix flats in ditches and side roads where the dirt is muddy and got on the cleats. Just a bit of cleaning with a stick and good to go.
I’m not planning to make a MTB-like messy use from my idea. It’s just a crazy option (again, already stated in my first comment, so I get it… not the smartest idea… I know… consider that horse dead…) that I am considering for a very particular use case (again, dry gravel with minimal off-bike use).