I have an i3 controlled by Home Assistant, it is on an "IoT" network without access to the Internet. Works like a charm. The integration allows to start, stop and view information like battery level, area cleaned, issues, etc. No mapping though.

The only caveat is that to associate it with a WiFi network, the legacy app is required. So if the app is pulled from the app stores, it may not be able to connect again after a factory reset. I don't think the pairing requires access to the Internet but it uses a bluetooth protocol that I don't think anyone reverse engineered yet.

Edit: I vaguely remember that mine also stopped working a year or so ago. I factory reset it, re-paired it and it has been working well so far.