DrRacket internal error for default save file location taken

On Racket v9.0 [cs], on a MacOS 14.3 (23D56) machine, if it matters, I encountered the following when autosave attempted:

copy-file: destination exists
  source path: /Users/jhemann/Library/Preferences/PLT-autosave-toc.rktd
  destination path: /Users/jhemann/Library/Preferences/PLT-autosave-toc-save.rktd
  context...:
   /Applications/Racket v9.0/share/pkgs/gui-lib/framework/private/autosave.rkt:57:6: notify method in autosave-timer%
   /Applications/Racket v9.0/share/pkgs/gui-lib/mred/private/wx/common/timer.rkt:34:38
   /Applications/Racket v9.0/share/pkgs/gui-lib/mred/private/wx/common/queue.rkt:436:6
   /Applications/Racket v9.0/share/pkgs/gui-lib/mred/private/wx/common/queue.rkt:487:32
   /Applications/Racket v9.0/share/pkgs/gui-lib/mred/private/wx/common/queue.rkt:639:3

The proximate cause is, as it says, that copy-file throws an error when the PLT-autosave-toc-save.rktd file already exists. But I don't believe I've done anything that an ordinary user wouldn't've done. It seems like we were prevented from clobbering an autosave list, but it surprises me that the autosave feature is limited to one list, or that the lists aren't addable, or that we aren't forced to dispense with the existing autosave list before trying to autosave the next one. IIUC.

I tried to look around, but I couldn't find where the prefixed k:copy-file is coming from in racket/private/pre-base.rkt.

Start at framework/private/autosave.rkt:57, the autosave-timer% notify method named in the stack trace, and inspect how the existing PLT-autosave-toc-save.rktd destination is handled. Reproduce autosave with that destination already present. Done means the reported internal error no longer occurs and the intended handling of the existing autosave list is covered.