My take-----if you ride a lot and trade often, just ride it until trade time. Let next worry about it.
I hate shims---I figure more difficult for guy at home-----As experiment, Suzuki GS500E---Checked valve clearances at home at 1,200 miles=ok but easier check than plastic scooter. Then as it was cheap bike with warranty----just rode it---15 months later and 64,000 miles, all ok as I traded it in. No valve/cam related problems.
SilverWing, after 30,000 miles I might want to check.
My Citroen BX 2000 no turbo diesel, shims, went over 400,000 km with no check---had servied in Italy (great) Germany (parts) changers and most often in Bitche France (great and skilled in the shop). Never valve/cam problem.....or anybody eager to check as pain in butt.