Arnold Neumaier pointed out, in this question from some months ago, that there is no "Improve" button for tag wiki edits that show up in the Suggested Edits review queue.
This affects users between 5k and 20k rep (as they can approve tag wiki edits but must have their own edits peer reviewed), so not everyone will see this. This population is about 30 users: admittedly not that many, but then only ~ eight other users can currently review edits (mods or >20k).
As Shog9 pointed out in his reply to Arnold, the alternative would be a cascade of edits to the tag wiki that would then need to be approved by someone else, and I understand this. However, this leaves a huge gap in the review process: what should I do if I see an edit I partly agree with but would like to improve? In the past I've approved them and tried to submit a new edit, but the system locks the tag wikis until a second reviewer approves the pending edit: I get
and clicking on
edit pending sends me to the history page of my review of the edit,
The only option, then, is to sit around and wait until someone else comes along and clears the edit. This is impractical because the tag wiki Suggested Edits queue is very slow. It is much slower than the corresponding post queue because ~100 users can access that. While I can see this is probably not an issue in SO, I imagine most of the smaller sites are in similar situations.
This has not usually been much of a problem, either, but the tag wiki editing activity recently increased by quite a bit. While I commend Dimension10's efforts to get me and a few others a Reviewer badge, this level of activity is not necessarily sustainable with the current tools this site has available. This is an issue because few people can review tag wiki edits and fewer of them actually do. Further, each reviewer can only do 20 posts per day, and I've already maxed out on that a couple of times. If you propose a tag wiki edit that takes ages to go through, that may be one possible reason.
I would therefore ask two things. On the site design front, is there a way to have multiple edits to the same tag wiki in the review queue? This would ideally be available as an "Improve" button directly on the tag edit (though possibly with text warning to make sparse use of it because of the reviewing limitations). Future reviewers might be presented all the reviews to the same tag wiki, either simultaneously or one after the other, to make reviewing simpler. A cap on the maximum number of pending edits would also be reasonable, as would making this feature site-specific so it gets turned off after the tag wiki review queue speeds up.
On the community side, on the other hand, if you have more than 5k rep, please review all the Suggested Edits you can. This keeps that specific queue faster and allows a faster community dialog about what we want our tag wikis to be.
I am happy to take the feature-request to the Mother Meta, but as this is mostly a local issue I thought I'd ask here and get some local support before I go there.