These tips are all solid, and reflect my setup. Database (MariaDB) and PHP files on the SSD, data storage on spinny bois. Don’t underestimate the importance of a recent enough version of PHP, OpCache, enabled, and so on.

There’s a whole chapter on performance tuning in the manual, and the “Security & setup warnings” part of the administration settings should point out some configuration issues, when it finds them.

My setup might actually take a (smallish) performance hit because I use btrfs for all my filesystems. Just don’t get roped into the whole “wsl on Windows” thing, that’s just not going to work out, it’s a kludge that MS offers to not bleed users to Linux too much, but it’s certainly not meant for server workloads.

The hardware should not be the bottleneck at all, the 1265 in OPs machine should not be significantly slower than the 1280 in mine.

Eh, my gen8 is chugging happily along with Nextcloud, Synapse, Jellyfin and friends, docker-mailserver, a GoToSocial instance, Home Assistant in a VM, and so on. I don’t know what else is running on your server (and, admittedly, I’ve added some RAM and stuck in a somewhat beefier Xeon CPU), but it should have no problems running a web app like Nextcloud, especially if you stay away from the more intensive stuff like office apps.

That aside, I’ve gone through a fair amount of note taking apps, and so far I like Joplin best, too bad it doesn’t seem to work out for you. Not sure when you last checked out the Android app, but I do know there’s been some changes in the editor it uses recently-ish, it might be worth it to check again.

I’ve used Rockstor in the past, I liked it mostly (but in the end went with a self-configured OpenSUSE system).

Apart from that, I hear good things about OMV and TrueNAS

NAT is not a security feature.