Dirt road? LOL. Even you can't be serious with this one. There are many reasons why the R1S is already more capable off-road. Maybe its not a modd'ed out rock crawler with 16" rims and ginormous monster truck tires, but it has already been proven capable in a variety of challenging situations off-road - situations where the BMW would struggle or simply fail. Come on.
Pinch flat on rocks are a real concern, I would say even more so in a ~7k lb truck. My 2013 LX 570 came OEM with 20’s, I negotiated in a set of AT tires and rolled with them. In the first summer I got stuck in the sand and had a pinch flat on a pot hole. The next spring I switched to 17’s, 8 summers later (knock on wood) I haven’t had a flat on trail and have not been stuck in the sand.
With all the trucks that come with 20”+ see flats all the time on forest service roads in the fall during hunting season, I see 3-4 every fall here in Alaska where there are very few people. Last fall come to think of it the only other trucks I saw on trails were stopped with a pinch flat. This is why range rovers and AMG G wagons are also completely useless off road as well.
I’ll admit I’m the kind of person that leans to over preparedness, and greatly favor function over form. Probably because I’ve spent a lot of time over the last >40 years in very remote and extreme environments all over the world, my time in service, my dad and grandfather hammering in me the 7p’s, and learning from mistakes.
people will probably be ok at a local off road park in an urban city where AAA can easily save them or on the easier trails on smooth rock areas like the SW US, much of Moab is like driving on hilly sandpaper. Any area with Soft sand, rocks much larger than a softball, and mud will be a no go. Given my experience No way I would feel comfortable out in the backcountry or even on any of our remote “highways” (Dalton, Steese, Taylor, McCarthy, Dempster,…) up here on 20’s
Just like in all driving scenarios tires are the most important factor: ground clearance, approach/departure/break-over angles, lockers, 4-motors,…. All don’t matter with inappropriate wheels/tires.