Yes I know Notion, and I’ve already tried AppFlowy several times.
The amount of stars they got on Github is quite crazy compared to… the quality of the app. I guess it’s only related to their main statement as being the “open-source alternative to Notion”, which is honestly a complete bullshit statement as of now…
They provide their app as a desktop release so no need for Yunohost to try it. Just download and run, and you’ll see. It’s still more than early stage, and I would even say not yeet usable as a notes app.
For the sync / online part, nothing has started yet, so you can only use it as a local desktop app.
It’s probably worth checking from time to time !
You can also have a look at Anytype, which starts to be a very good app (and IMHO much more promising in the long run) https://anytype.io. The team has promised that they would release it as a open source but everybody is still waiting. Also, to get to try it you’ll need to register on a form, then wait for 2 weeks, then have to attend a one hour zoom call with the team before you can get a link to download.