The other technique i heard thrown around, in the aftermath of the tail strike day, was VR should be somewhere close to your GW in 100K lbs. Like 165k would be close to 165 KCAS VR. It’s really loose, probably +/- 20 knots from actual # in some instances. But it would theoretically trap a Vr of like 120 knots, on a 170k jet. I also have no idea where i heard that, and it isn’t something i use for any actual verification, but i have paid attention since then, and this ROT seems to be kinda ballpark most of the time. That of course doesn’t address the wrong power setting potential issue, which is more of a line speed check thing like you mention. I honestly dont think there is a really good ROT possible though, we use so many crazy derates/AT/etc, I’m not sure anything could ever be accurate enough to verify. If they actually included it in the performance pack, then that would be something potentially useful. I do know that when i look outside and note the position down the runway at V1, it almost always seems like it would be an impossibility to stop in the distance remaining (yes, i know it actually is possible up to that point). So it is damn close to using up almost all the runway on a normal takeoff with nothing going wrong, the way we derate these things. Guess that’s a long way of saying it would be hard to have a consistent sight picture for “what looks right” given that, different runway lengths, etc.
