Why is doing a factory reset not recommended when toltec is installed?

[Groxx]

The FAQ on toltec-dev.org mentions:

Can I factory reset my reMarkable if I have toltec installed?
No, DO NOT factory reset your reMarkable if you have toltec installed. First uninstall toltec with toltecctl uninstall.

I don't see any mention of why though.
What happens if you do end up doing a factory reset? And how do you recover from it?

I'm broadly assuming that it means you'll have to do something like ssh in and re-enable xochitl, so it's just more troublesome than desired, but details would be interesting and potentially useful for anyone who missed that FAQ entry.

[LinusCDE]

I think @matteodelabre might know this better, but my assumption is the following:

A factory reset only wipes user data. If this wipes/resets /home, this could make your current system unbootable since you might have an alternate launcher selected which now no longer exists (launchers usually have a fall back though). But there are other things that can prevent a boot apart from an alterantive (now missing launcher).
Reason is that the extra software has "a separate filetree/root" where all libs/binaries are installed to: /opt. This is in fact at /home/root/.entware. So a binary found at /opt/bin/somebinary is in fact at /home/root/.entware/bin/somebinary. Removing this directory would not remove the service file that wants to mount that directory to /opt and thus could prevent booting.

[Eeems]

As @LinusCDE mentioned there are things installed into root that will not be cleaned up when a factory reset is done. This requires users to know what to manually clean up in order to get xochitl started again, and to get back to a factory state. Which is obviously not fair to expect of most users.

[matteodelabre]

The only thing I’d add is that users can always do a “real” factory reset by following instructions from https://github.com/ddvk/remarkable-update, and get back to a clean system. But this may not be an easy option for all users, which is why we recommend people don’t use the standard factory reset option.