Small Server is a small crossplay SMP hosted on x240 and tuned pretty heavily, so it should run nice and smooth. It's running on FreeBSD too, and if you want the best experience they recommend joining with 26.1.2 and using Temurin JDK 25.
The worldgen isn't plain vanilla either. It has structure mods plus Terralith and Tectonic for better terrain, and they've already regenerated around 3 million chunks for everyone who wants to explore a fresh world. is coming soon too, thanks ^^