I count the actual moving time, Pro Bike Garage uses the moving time. Roughly equates to every 3 months for lower leg and aircan services (do the dropper at the same time).
One of the EWS/DH suspension techs said the 50hour interval was about right, if anything would recommend more often if you are racing or riding more challenging stuff.
Even when uplifts were allowed, they dont make a huge dent in the total ride time. If I’m doing a week in Inners/Golfie with a couple of uplifts thrown in or a fortnight away, I’ll service the suspension before I go and quite often will be servicing peoples suspension when they complain of arm pump.
My old Boxxers were 25 hours recommended, 10hrs if you fitted the low friction seals! In reality DH bikes see not a lot of use, so not a problem, but two weeks in Morzine and they did start to feel sticky towards the end.