The definition seems a bit limiting to me.
However, I think Ckeditor is (https://ckeditor.com/). You can find it in component format for tilepieces in the project https://github.com/tilepieces/component-examples.
74 karma · joined April 6, 2022
Please note that you can upload an existing project -> https://tilepieces.net/documentation/panels/package-manager/.... Zip a folder and start editing!
As for the windows (I think you talk about panels -> https://tilepieces.net/documentation/UI/panels.html) they can be set right, left, above, below (they are fixed below 1024px). They are certainly a bit .. rough/raw/sketched i think you could say... as everything to the UI, but at the moment I think the important thing is that they work.
The third point you are referring to is a bug! I swear it worked until yesterday :)!