This Ren'Py feature is utterly annoying. More than a feature, I would call it "a bug by design".
There are ways around it, but it requires the developer to deal with it.
For example, using the slotname callback (
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), which was added a couple of years ago, and mixing that with a regexp when listing saves or slots. The other options are more complex, but revolve around swapping the config.save_directory value.
But it does require the developer to implement it, because anything more complex than a basic 'save' option requires a lot more work.
As it applies to Harem Hotel beta releases, it's not really worth Runey's time/effort. If someone wrote a workable solution, and stuck it up for everyone to use, then maybe it'd find its way into testing patterns for games, but there's little point.