At nearly 82K miles, I've been all through this one already. Several times, in fact.
BMW put in a software "feature" that watches how the bike is ridden, then estimates when valve checks should take place. No, I don't know exactly what it's based on, or how they calculate the number. I don't think anybody does (maybe even including BMW
But customers stared complaining because they would come in for a full service, then find out a thousand miles later that a valve check was recommended, thus requiring another full service visit. Much like you've found.
So BMW changed the recommendation to every 18K miles, to coincide with a "normal" service interval. I told them to check my valves at the 18K service, but the dealer (not one of my two favorites) declined, because they had never done one before and they didn't have all the proper tools and shims. I agreed with that choice, rather than being stuck out on the road somewhere waiting for parts. They did tell me that my bike's computer recommended a valve check at 24,600 miles.
So I had my normal dealer do the valve check at the 24K service, and all were in spec. It's been checked twice more since then, and no shims have been changed yet. In fact, after following 5 different GT forums for the past two years, I've only heard of maybe 2 or 3 bikes that have needed shims changed (easily over a million GT-miles ridden).
It's probably time to check it again. I'd like to do it myself this time and maybe even take pics and write up the full procedure, although I don't have all the proper tools yet (hi, Grif
So the summary is that I'm pretty sure that you can wait until your next major service to do the valve check.
'13 Dark Graphite Metallic K16GTLD, 24K miles and counting...
'09 Magnesium Beige Metallic K13GT, 60K miles miles and counting...
'02 Mauve Metallic K12LTC, 106K miles and sold
BMWLT#145, IBA# 366, MOA# 111996, SCMA# 24032
All lower 48 states plus Alaska on the K13GT in two weeks . . .
Some people see the gas tank as half empty. Some see it as half full. All I care is that I know where the next tankful is coming from...