Looking at it, half the job of checking clearances is getting to them. I sincerely doubt mine were checked. I bought the bike on 13000 miles, and as part of paying the full (reasonable) asking price the dealer agreed to do the 15000 mile service early for me. Guess I'll find out when I see the state of the air filter when I do my own service now she's hit 15000. If I had stripped it that far, the little extra to get to the valves would seem a no brainer.
Actually changing shims is more time again though. At least these days I have other transport options. My first shim change was 20 years ago on my speed triple. Strip and check, shims needed, so rebuild, go and fetch, strip and fit. Can't say I miss those days!