"Slightly off thread I find a lot of pilots do not turn the fuel selector to OFF at the termination of a flight "
Personally - I never do this as I think it is safer to keep it on.
If I walk up to the aircraft and it is sat in a pool of fuel I am not going to fly it! If I switch the fuel off I may not find out about the issue till later...
The fuel selector often has no maintenance schedule. I know of a number of aircraft that have suffered fuel selector failure at the point of max fuel pressure - normally just after takeoff and the pilots have been killed or burned - and one when the pilot was sprayed with fuel but got the cub down and it did not go bang.
I check my selector every 3 months. This confirms it is working.
Rod1