Is there a query that would identify the phantoms/zombies so that we can check that they are being cleaned out?

As an aside: The query is possibly incorrect – more so if cached.
The status of the user at the moment they made the edit is the correct detail, not the status of the user now.

( @Jeff_G FYI:
The rows of the watchlist have classes derived from the query — mw-changeslist-user-experienced, mw-changeslist-user-registered, mw-changeslist-user-unregistered etc.
I am not sure what currently makes use of these classes (I could not find anything), but they would be available for a skin or user script to add some sort of "confidence level" branding. )

Random e-mail from today for an edit:

Not sure I fully understand the question.
A "change" is when a page is edited.
"Reviewed" is when a reviewer has marked the page as "reviewed".
They both trigger e-mails saying "changed".
It would be friendly if the e-mail made a distinction between editing and tagging.

see T315858 re right-align

see T315870 for a screenshot

Before this is unleashed, please could you post here the actual new heading HTML, so we can plan for any necessary user script changes.

@IKhitron Not sure if you still have the need to know if a template is in the article lead, but on EN WP there is a module that tests for an Infobox being in the lead section.
You may be able to adapt that for your case.
See Module:Is infobox in lead

FYI
My WatchlistTidy user script moves the "View new changes since ..." prompt out of the collapsed area and also moves the Hide/Show toggle to the right as show here:

see also T315870

Sort of, but no. Please sort them into a consistent order

Please confirm that this change is also valid for legacy Vector

It would also help to increase the size of the dots from 6px to make a better click target.
This looks about right:

.mw-rcfilters-ui-changesListWrapperWidget .mw-rcfilters-ui-highlights > div {
  width: 9px;
  height: 9px;
}

If there are style issues in a specific situation, then the solution is to change the styles, not the DOM.

When will the bodyContent ID be renamed to mw-body-content and where can we track this?

Please could the Devs make a statement as to the "correct" way to add new content at the top of a page?
Is there a definition anywhere of the IDs that define the main structural parts of a page that are valid for all skins and where some essence of contract exists to ensure that these IDs are future-proof?

Safemode looks really weird ... but no errors.
What happens if you switch to real Vector?

Logged in as me -- https://en.wikipedia.org/wiki/User:GhostInTheMachine
Skin = Vector legacy (2010)
ALL user scripts disabled.
Windows 10
Brave -- Version 1.41.96 Chromium: 103.0.5060.114 (Official Build) (64-bit)

Maybe double the thickness of the edges and close the corners?

If you report this error to the Wikimedia System Administrators, please include the details below.

We plan to show these headings to non-screen readers as well

Which ticket should we watch for updates on these plans?

+1 for a tabs prototype. If you use "TOC" and "Tools" there should be room for 3 tabs. (I would create a third tab for my users scripts.)

Also remove the extra date lines on desktop skins (not just hide them)

Remember also, that a "bad" Short description is often not reverted -- just re-edited. Do the stats just test for the "revert" tag?

Once the namespace is disabled, what error message would be displayed when a user tries to access a missing Book: page?
Are we able to modify the text of this error message to explain the absence of the former namespace?

Please check / update / clarify the introduction at https://www.mediawiki.org/wiki/Manual:Interface/JavaScript#mw.config

On the English Wikipedia, the article description is local and should start with a capital

I know that this is closed, but FYI.
On the English Wikipedia, the article description is local and should start with a capital.

I understand what you mean, but ...
The change wanted here is not to turn off the polling when Live Updates is turned off, but to have a further option to fully turn off polling.
I would also distinguish between polling and pulling. The GET request is just asking for a "did something change?" status and does not pull any data.
The response for no change is a 204 with no payload. The response after a change is a 200 - also with no payload.

I think that the original title was more correct.
The request should probably be instead to change the 2-way Live Updates button to a 3-way option:

• do not poll — but allow a manual refresh of the history display without a full page reload
• poll and stop — as current non-live
• full live update — as current Live

Also now a problem on en.wikipedia.org. ext.categoryTree is not being loaded

FWIW -- a quick heads-up at https://en.wikipedia.org/wiki/Wikipedia:Village_pump_(technical) is often a good idea.