Koreader doesn't sync deletes from Dropbox

[dsjstc]

TLDR: I want the Koreader client for Dropbox to delete local files that no longer exist on the server. Is this a config setting that I haven't found?

Long:

I would expect a cloud-storage syncrhonize action to end with the local client matching states with the server. Ideally local changes should be pushed to the server, but at a minimum, files missing from the server should be deleted locally.

This doesn't seem to happen with the Koreader Dropbox client, and this seems like odd behaviour! When I'm done with a book, I'd much prefer to delete it from my reading queue *once*, and have it deleted on all of my reading devices.

I have observed this behaviour on Koreader 2023.01 on several different devices, including a couple of android flavours, a kindle, and a kobo.

Is there a fix or configuration available to make this behaviour match my usage pattern?