I just set up my own sync server. It is dead simple with docker compose and pretty well described on their git page.

Getting my own auth server up and running was a bit more difficult, but it is absolutely doable. There a a few ppl who have made scripts to ease the task. You can find them on github.

Nør for military communication. Just for public info

There is a reason the Russian government allow the use of it and even let their military use it - and it is not due to security! They have a backdoor into the chats and UAE it actively for listening in on things and spreading propaganda and disinformation.

From a privacy perspective: no

From a fairness and repairability perspective: yes