

Matrix seems a bit overkill. I think they would be better off with something like gotify.
Take a look at dontkillmyapp.com to see if your phone provider hinders your messages.
There is unified push as Google alternative as well, which works with the schildichat matrix client.
Blue LEDs are the worst offenders. No need to return it as long as you keep a bit of black tape ready. If you still need it as an indicator, you can use layers of yellowish tape. The one used while painting your walls works great. Masking tape it’s called in English.