A common problem I've noticed in the reopen review queue is that if an edit is made while the review task is active, the task's view shown changes from the question to a diff view of the edit. This changes the whole focus of the review from the question to the edit. This means that many reviewers review as "Leave Closed" if the edit is very minor, even though the question itself is in a reopenable state.
The official advice given is for users to review the question, not the edit:
Likewise, don't fail to reopen questions that were closed incorrectly just because the edit was minor - they still don't need to be closed. You're not reviewing the edit, after all: you're reviewing the question!
Yet because of how the system works (the edit is shown by default), users still tend to just review based on the edit. Some of these questions are substantially overhauled shortly before getting their final close vote (possibly by inertia or carelessness); if they are then edited again, this happens.
I once made a minor edit to one of my own closed questions on a certain site, that another user had voted to reopen. The problem is, as there was a pending reopen vote at the time of my edit, the whole focus of the review task changed from the question itself to my minor edit. A moderator made a binding review as "Leave Closed", and they later clarified that they did so because they only saw a minor edit. (It's worth mentioning that I voted to reopen the same question later, being sure not to make any edits, and it was successfully reopened.)
I understand that the diff view is very useful in many cases, such as if the review task was created by an edit within five days. Ideally, I'd request that the diff view only be shown if the task was created as a result of an edit within five days, and not show it if the task was created by an external reopen vote, but I see that as being potentially controversial.
I originally proposed another way (10k-only) to solve this problem, to show reopen reviewers the number of reopen votes on a question, because if they only saw an edit but there were active reopen votes, they'd judge that there's something else about the question and more fully consider it for reopening. However, it was negatively received, as people were concerned that reviewers would simply follow along with other reopen voters rather than make informed decisions.
I'm also aware that reviewers can click the "Question (revised)" tab to see the question instead of the diff, but as was demonstrated by the above scenario, most reviewers, including some moderators, don't bother to click on other things when reviewing.
How can we get users to follow the official guidance and prevent reopenable questions' reopen effort from being derailed by minor edits?