I agree 100% as that has been the case with my pre and post lc engines too and the K1600 appears to enjoy the same reputation judging by the shared experiences from owners I've chatted with and in the various K1600 forums. That said, I don't think it's fair to say the OEM recommended major service interval may not have to be followed so disregard when comparing +/- of a tool for a particular job. Anyway, as I mentioned above neither option is what I would choose to take home even as appealing they are. I've ridden cross country many times on my BMWs of various shapes and sizes (R, S, F) as well as aprilia, Triumph, Guzzi, Honda, Harley and Victory and while they each treated me well/never broken down they all had little objective things I wished I could incorporate from other models or Brands. Worst thing that ever happened was a bunch of fun riding and hoping to be able to "repeat often" as my Bucket List only gets longer each trip.That’s fair. I’d wrongly assumed the concern was the effort to do it yourself. If you have to schedule service while out on the road, I could see that being more challenging if you are doing so many miles a year. Longer service intervals would be an advantage in that case.
My hunch is BMW is being very conservative on the valve checks on the R18 as it is a new engine for them. I’ve never had to tweak valve clearance on my boxer bikes past 12K miles. They stayed in spec after then. I wouldn’t be surprised if the R18 behaved similarly, so it may be possible to extend the valve checks beyond the 6K.