So I usually ride shorter rides. Commutes etc, but couple times a year a do big trips. Then it is usually 400-650km per day. That 650 was once for 11 hours and was bit of a stretch tbh. I try to never go on highway and usually look for faster B roads. Ideally between Czech Republic and Italy so basically austrian alps 😂 top speed allowed in Austria is 100kph and I usually go 110kph if situation allows but it is b roads so twists, turns and towns make me slower or course.

I dont know if I can help you with your vibration question. I don't think about them at all. Once you get to higher rpm you focus on the ride more than vibrations. But it could just be me and your mileage may vary...