Save As does not remove the undo stack

(InDesign 21.5.1, Windows 11 Pro)

There have been (are) several problems with InDesign’s Undo feature, to which a new one (as far as I know) can be added: when you Save As a document, the undo stack is no longer removed. This is a problem because over time, a document’s size can increase enormously. Reported here:

https://indesign.uservoice.com/forums/601180-adobe-indesign-bugs/suggestions/51605780--save-as-doesn-t-clear-the-undo-stack