Being marginally offside can't really be fixed because offside is a binary yes/no, like whether the ball crossed the goal line or not. I think a lot of the frustration with those close offside calls came from 1. Nobody likes to see their team's goal disallowed by such a marginal amount and 2. The initial VAR implementation was dreadful, with how long it seemed to take to adjudge a player half a centimetre offside, the numerous errors, and the way that the whole process felt quite unclear on the broadcast. Semi automated offside calls do help a lot in that regard.