I see how making it fix a broken wheel whenever it is broken is contributing to the other miners. but I'd have to agree, it makes it look very robotic. Maybe have that check every three trips, or more if the expanded sack is checked. That would definitely speed it up and still would make it fix the wheel if it's broken on the final trip.
I see it also uses the amount in the sack to decide when to check it, and if the wheel is broken and ore not flowing. it will not know to fix the wheel and/or check the sack. Would be very efficient though if it didn't wait and fic the wheel every time lol.