I think the focus of VAR is just wrong. I don't care about a goal where a player is a millimeter offside. That's just pedantic and slows everything down. Sure, if you can see it clearly and the guys off by an obvious amount, call it back and do it quickly. I don't know what the rule needs to say for that, but maybe a ref uses some discretion? I realise that's a slippery slope though.
I also think that they should be targeting obvious fouls and make it known it's coming. Wrapping players up and grabbing them in corners and free kicks, diving, etc. Should all have a publicized campaign to clean things up. If a team gives up 3 penalties because of it, they're going to change their actions in short order. To me, that's how they should use VAR though, not this five minute delay to see if he's one pixel offside in the buildup garbage.