I split it into big and small revisions.
Small revision is after one race or about 2 or 4 hours of running, it depends a bit on the track. I will do: Complete cleaning, changing of middle diff oil and bearings, clutch bearings, shock oil.
Big revision/complete rebuild is after about 8 to 10 hours or sooner before an important race. Complete disassembly. Change all bearings, all pins, all oils, clutch shoes and springs, replace worn links or torn rubber boots.
Everything else is basically setup change or repairs. All maintenance during races is new air filters and clutch bearings.
Your cleaning and maintenance cycles will depend a lot on where you run and how abrasive that surface and the dust and dirt are.