VAR should remain in its current form for offsides only in my opinion, with the captain of each team having two appeals to use during the match to challenge contentious calls such as penalities or straight red cards.
The biggest issue with VAR is the criteria in which things get referred back to the referees which is leading to far too many inconsistent calls. Just using Everton as an example, why was Allan's red card sent back to the referee whilst Jordan Ayew's challenge on Gordon was not? The VAR officials are hiding behind this 'clear and obvious' nonsense rather than just assessing each decision at face value.
An appeals format I think would allow the onfield referee to go about his business more freely without thinking that every decision he makes/doesn't make is being scrutinised at Stockley Park, whilst teams would have it in their power to dispute calls which would remove the inconsistency that we're seeing.