The server was updated to 1.20.6! It was a bit of a hassle as I had to figure out how to update java on a Debian 12 server as natively it only goes up to vs. 17. And MC now needs a higher version of java. But it works now, thanks to this reddit post.
Spiggot is also running along with Dyn map and backup plugins!
Today I added both these mods to the server. They are included in the downloadable zip file, linked at the server info page. Also Refined Storage was updated to 1.65 which features bug fixes and faster autocrafting, so I figured I might as well throw this in as well ;).
Both these mods should be fun to play around with. Immersive Tech features a huge steam turbine amongst other things, in the Immersive Engineering stylle. PneumaticCraft: Repressurized has some unique mechanics featuring an air compression chamber. It also adds some more fuels like LPG that can be made from raw oil, so more fun machines to set up :).