I am basing it on the existing offside rule, I am not a fan of it either but based on the current offside rule, it can be definitive. The world moves on, and I am not saying I agree with it, but it does and VAR is clearly here to stay. So unfortunately your idea of going backwards won't happen, however, I believe limiting VAR is definitely an option and giving them offsides to deal with is one clear area that it could work based on existing rules.
Changing offside rules is a completely different debate. To state it is my offside theory is wrong, it is the current rules. I didn't make them up.