It took more than 20 seconds to load this page in debug mode:
https://pt.wikipedia.org/w/index.php?title=T%C3%B3pico:Ss6qo681yhzwceha&action=undo-edit-post&topic_startId=ss6qo6cqbsxwwjta&topic_endId=ss6w8enh3dnd9ghv
This is not the first time I had to wait that amount of time to load the comment form in Flow pages when in debug mode...
I would prefer it be faster too as a developer, but debug mode is not for normal usage. Also, this is really probably 90+% on the VE side, and not easy to fix (though there are bugs that would obsolete it like T47514: ResourceLoader: Implement support for Source Maps).
We might be able to not load (though a lot is accessible through keyboard shortcuts even though it appears not to be visible) or lazy-load more stuff as well.
It might also help to change which VE target we use (there is a bug for this somewhere).
So putting back Flow for now.
Well, how else can I find the source of bugs such as T110182 if not using debug mode? An URL like
https://pt.wikipedia.org/w/load.php?debug=false&lang=pt&modules=ext.centralNotice.bannerChoiceData%2CbannerController%7Cext.centralNotice.bannerController.lib%7Cext.centralauth.centralautologin.clearcookie%7Cext.uls.init%2Cinterface%2Cpreferences%2Cwebfonts%7Cext.visualEditor.desktopArticleTarget.init%7Cext.visualEditor.track%2Cve%7Cjquery.byteLength%2Ccookie%2CtabIndex%2Cthrottle-debounce%2Ctipsy%7Cmediawiki.Title%2CUri%2Capi%2Ccldr%2Ccookie%2CjqueryMsg%2Clanguage%2Cuser%7Cmediawiki.language.data%2Cinit%7Cmediawiki.libs.pluralruleparser%7Cmediawiki.page.startup%7Cskins.vector.js%7Cuser.defaults&skin=vector&version=71829dff924d&*
is not very useful...
As a developer, I definitely understand the need for debug mode. I just use it on an as-needed basis, though (sometimes using your script), and deal with the VE slowness. As I said in my follow-up, there are some things we can maybe do about this (short- and long-term).
With the source maps which are meant to have arrived years ago; see T47514: ResourceLoader: Implement support for Source Maps towards the top of this task's dependency chain.