Your comment was true, but not exactly relevant since we were talking about airtag-like devices that don’t have connectivity besides Bluetooth, saying that a device like them exists that has GPS built-in is kind of moot since they don’t have any additional ways to send that location info.
The thing you linked would fall under the walkie-talkie-like device I described.
You got a typo for mastodon (mastadon)
I don’t really have any input on how it is to self-host, but I’ve been playing around with friendica a bit and I think that has a lot of potential and may be worth mentioning. I think it has a lot of potential as almost a unified fediverse portal in addition to its obvious purpose of being a Facebook alternative, from what I’ve seen it seems to play pretty nicely with a lot of other fediverse services, and also supports RSS feeds
It needs some polishing, I think the default UI is pretty wonky, but there’s a lot of functionality there if you can be bothered to figure it out.