IMO coaches challenge on missed calls should only overturn the call on the ice if there is a margin of error. Arbitrarily, I'd use 3-4 inches with reviewer discretion to do less than that.
3-4 inches on offside
3-4 inches of goalie movement impedance in a goalie interference
3-4 inches via high stick
Obvious penalties missed prior to goal
etc.
However, the point isn't to put another step in the review process, it's if it's super close that you can't figure out what the issue is within 30 seconds vs spend 5 minutes looking at the play frame by frame, call on ice stands. This is to reduce the time the review takes and keep the flow of the game going. Challenges should be 1 minute or less. Not up to 5-10 minutes.
Coach doesn't lose challenge if it's within the margin of error.
This will deal with things like egregious uncalled penalties prior to a goal or something like a player somehow being a foot offside with no call that coaches had no way to challenge in the past. But gets rid of the stupid thing where coaches can call everything.
Either build in a margin or error, or all goals must be reviewed prior to play continuing. Not this weird, whatever in between thing we have right now with no consistency.