I’m confused, the author asked at the end of the article what should be included, and so I brought up what I thought should be included. I wasn’t trying to criticize the author at all.

Monero and chat applications (eg SimpleX)

I haven’t personally tried it, but I think there’s a setting in the mobile app for using it with a desktop. So I assume it is fixed, but I won’t swear to it.

You may want SimpleX. You can still self-host your own server if you wish, but it doesn’t have nearly the metadata issues of matrix and encryption keys are stored in a database that you back up instead of constantly breaking