This previous Meta question, Warn when approving edits for questions on hold, deals with not approving edits to on-hold questions that don't solve the hold issue. It proposed a warning to alert the reviewer.
The issue is to not waste reviewers' time by dumping the question into the reopen queue when the close issue has not been addressed. The question is also bumped on the main page (reducing attention for new questions), even though readers are still unable to answer it.
The problem is not limited to approving edits, it also applies to improving on them. On several occasions, I've seen an edit that contained some glaring error, or overlooked some other needed fixes. Those issues were the only obvious problems.
When you are focused on one shiny problem, it is easy to overlook checking for other, unrelated ones. I just went ahead and fixed the edit without opening the question in another tab. I discovered later that the question was on-hold for a reason that didn't jump out in the review queue, and neither the proposed edit nor mine dealt with the hold issue.
I would like to propose an alternate (or additional), change:
In the edit review queue, the question should display the same "(on hold)" label in the title that appears with the question on the main page and when opening the question in its own window.
People get accustomed to seeing on-hold questions identified in that manner, and the edit review queue is the only place it is not displayed. Lack of the label there leaves no indication that, in addition to reviewing the edit, the question should be double-checked for reasons it might be on hold. That's important information that shouldn't be left out, and it is especially relevant in the edit review queue.