U_Fischer

If you use a dedicated loader as wrapper you could naturally redefine it at begin document again. Inside the document body the machinery is not really needed. But I will discuss the \@pushfilename/\@popfilename question with the team.

Setting fontsize in expl3-context gives warning

typo in KOMA-code: \@dottedtoclilne

\recalctypearea looses text when used in twocolum mode

The \let\scr@pkgextension\@pkgextension is not the problem. But the \AtBeginDocument around it is a problem as it starts the typearea chunk. Try it out. And if I would use begindocument/after for changing \if@atdocument to \iftrue now after several years, this would be much more incompatible than moving it to begindocument/before. And it would not help me with my own packages. I agree that moving to another hook doesn't improve the situation. The switch from false to true would still not be at a...

\AtBeginDocument{% \let\scr@pkgextension\@pkgextension } is before \RequirePackage{scrkbase} in my version of typearea and that triggers the chunk. Or maybe I should declare \if@atdocument as deprecated Well I find the switch a bit curious as it changes to true somewhere in the middle of the begin document hook. For me the document starts only after the hook, as you shouldn't do typesetting here, so from the description I expected it to be false in the hook. BTW: pagesize=auto is the initial setting...

I don't know why there is a \AtBegindocument before scrbase in typearea or why you have to guard the \AtBeginDocument code of typearea with \if@atdocument. But if this is necessary you could use a manual label or the push/pop system or simpler (inside a package) \SetDefaultHookLabel to separate the chunks: \documentclass{book} \usepackage{lipsum} \AddToHook{begindocument}[typearea/beforescrbase]{\def\AAAA{}} \usepackage{scrbase} \PushDefaultHookLabel {typearea/afterscrbase} \AddToHook{begindocument}{\def\BBBB{}}...

pagesize has no effect if typearea is used with standard class