The github repo mentioned this wiki article for multiplayer performance tweaks. Did you run through this list and make the recommended changes?
Notepad++ if you just need to type something up.
Trilium Notes, Logseq, or Obsidian.md if you’re looking for something more advanced.
Self-host something like bookstack, docuwiki, mediawiki, or wikijs for something more… permanent? I wouldn’t really use these to jot something down real quick but I do put a lot of finalized? notes in a wikijs docker image I host.
Warframe has gotten so much better since 2020. I highly recommend coming back for a bit just to do the new quests. All your stuff will still work great in the new content. In fact, it’ll work better now that other damage types are way more viable. No longer have to mod everything viral/slash/heat.