Very serendipitous, I recently made almost the same thing, but for Leo Editor (leoeditor.com) instead of TiddlyWiki. Leo's tree-style organization/UI seems to w

Very serendipitous, I recently made almost the same thing, but for Leo Editor (leoeditor.com) instead of TiddlyWiki. Leo's tree-style organization/UI seems to work perfectly as "second brain" for me, and I've been using it as such for years. I was getting fed up with not having my notes on my phone, so I finally wrote a mini-Leo PWA, with an equally minimal sync server like in this article. I immediately fully switched to it. The whole thing is way more crude than this author's though, especially the sync. That's literally implemented as two buttons in the app, "send to server" and "load from server". Better not hit the wrong one :D