The main problem had to do with fields inside a custom component not updating the tree (document JSON?) properly. These components could be nested, they had each a title and another variable-content field into which other components could be nested into. The title was a div.contenteditable and I had a hard time getting it to sync with the tree, some components were never able to do this. https://imgur.com/a/qKg9UUs (SFW, apparently imgur has a new policy?)

It might be somewhat similar to the "details" extension, but they were also drag and droppable. The drag and drop support was also somewhat subpar compared with TinyMCE, I ended up using vue.draggable.next to solve the issues, but this added a layer of huge complexity.

Then there was an issue that the UniqueID is a Pro extension and it would have been required for properly storing the document. I now see that pro extensions are free, after registration, but I'm not sure if it was always like this, I think it was coupled to a GitHub sponsorship back then (maybe around August 2021). For a side project which would then sit at rest for some months this wasn't feasible. I think I implemented a custom UniqueId to get around this, but I haven't touched the project for over a year.

About 2 months ago I was thinking about rewriting it in React and see if I could turn it into something, but I haven't found the time.