AFAIK, only Joplin offers sync with NextCloud.

On mobile, sync works well, even with 2FA. But my access model is simple: 1/ create and edit notes on Desktop app 2/ read notes on Desktop and Mobile apps.

This looks cool, but can’t beat Joplin. Accessing securely my notes on multiple devices I synced on my Nextcloud is priceless.

Chuck made a great video explaining that. If I remember well, he suggested 2 Wi-Fi, one to connect to the hotel Wi-Fi for example and the other to distribute a secure connection to your gears. I guess you can do the 2nd one through the Ethernet port of the Pi: here you go.