Maybe this solves your problems? It creates a database in your browser's LocalStorage.

https://noteself.github.io/

And the database can be setup to sync with a self-hosted CouchDB instance.

While that works, the original appeal of Tiddlywiki was that you could open a file in your browser, type away, and save naturally. Once you get into "self-hosted", you just have a regular old wiki. I used it everyday for several years but gave up once the transition happened. I keep trying to go back, but it just can't compete with files edited in a text editor and stored locally.

I used to run it on node but then I switched to notion I prefer the notion way much more. However I'm looking to move away from notion to something selfhosted.

My coworker used to swear by TW and every once in a while when I read browser release notes I have wondered if it still works for him.

It sounds like you're saying that nobody bothered to modify it to use LocalStorage, which is a surprise.

I run it on a webdav server like caddy, there is also this ruby script you can start. Works ok, set it up once and you forget about it.