Marking the scope would work, although there is a tolerance there too that needs to be observed and measured.This will probably catch on before Stanley and I make any money taking up Rob's scope re-reticling business suggestion.
Sig and other companies have scopes that can overlay holdover points with data fed from rangefinders, digital scopes are a thing but with drawbacks. It's getting closer.
Perhaps I will start a scope company that puts a mark on the bottom of the scope that lines up with a mark on the bottom of the rings so there isn't a scope leveling discussion every week. That seems doable.
ILya