I have come across a nice piece of work uses tlDraw to create html UI.
SawyerHood/draw-a-ui: Draw a mockup and generate html for it (github.com)
(This is an app that uses tldraw and the gpt-4-vision api to generate html based on a wireframe you draw.)
This feature can be used in TiddlyWiki. So, people with little CSS/Html5 knowledge can create nice UI in the fly! @linonetwo has already created a plugin for tlDraw, so you can do all in TW at the cost of running it on Node.JS.
I am sure people here will find a way to do this.