That’s pretty nuts, I thought those were cruiser tyres specifically with softer sidewalls, whereas sports tourer tyres have those stiff sidewalls for better handling. I think all the K1600s I’ve seen, similar weight, had Metzler Roadtecs or Z8s on (great tyre BTW, always rated a Metzler front tyre, even if they wore out quicker than the Michelin, lovely while they last).
Still, sounds like an interesting characteristic to get used to. Always wanted a go on a really massive cruiser/tourer, but I struggled with my tutor/observer’s Pan European, made me realize that the RT’s design was a lot cleverer than I thought.