

I selfhost a matrix instance just for myself and my bots. And send myself notifications to the phone client element. I can even trigger a fake VoIP phone call for really important stuff.
Notifications come through as any other message app notification. And calls do the same.
In order to get all notifications and not destroy your phone battery I found out that you need to download the google play version as you need google services for notifications.
Not at all. I have my instance sitting on 100MG of RAM and 0% cpu usage. There’s only 3 users that barely use it, but there it is.
It scales by number of users.
It’s true that it’s a resource hog, due to being written in python (who the hell though that), but it all depends on usage.