I was talking about this docker image: https://hub.docker.com/r/collabora/code/

correction from my side: it is the development edition, which means rolling release and possibly less stability, but it is worth a try imho (but i do not use it personally)

you can set up collabora without nextcloud, as well

i find the latex fonts weird to deal with. for me it is more a thing of setting up your template the way you want it and keep sailing with that.

edit: typo

you could have a look at etherpad. seems pretty cool and is extensible with plugins. i don’t know about resource consumption and security aspects, tho, because i don’t personally use it. there are also a few publicly usable instances to test it out (see their github). keep in mind, however, that those come with plugins and do not reflect the vanilla state of the tool.