
I have become a user that uses the HTML editor quite a bit to format sections of text like in the Metadata window (and other custom columns - I use one for notes especially - and have it append to the metadata that is in the book description section - the preprogrammed window I basically use for a description of the book (this is especially true of a library I use for all my music books and music lessons (some video lessons, some books with videos and/or audio file, etc.. I also use it to link to other books or lessons related. And some entries are used primarily just to have an entry - for this usage - where I put and update my lesson and practice plans, etc. I have found calibre as it has grown - especially to have a data folder for related files - to have become extremely well suited for this.
But in the second editor window - Normal View and HTML - I put more coded markup language (and have even gotten used to using AI to generate what would often be tedious code

).
This way I can edit it without all the clutter from the programmed window's description of the book or lesson. But I was wondering - I don't know if this could be added (I don't know if the HTML editor is a package that can't be changed (added to)) - but would like to see this if possible in a near future update.
I am in the habit of using the html comment tags when entering data - especially when using Copilot to generate it - to do it in chunks - most often utilizing tables - that because of the character limit 9REALLY SMALL) in Microsoft's CoPilot (I hope as time goes on - this will be increased) - I have the code broken into logical chunks - and mark these chunks with the comment tag. In case I have to go back and redo something - which even with AI is common - it ain't that intelligent) That is fine as long as I don't submit it - because the editor automatically in rendering it into simplified html - and even adding corrections or closing tags (even when not necessary such as </p>) - which is a great feature in itself. Then I lose those chunk marker comment tags - and any others I would like to use to indicate particular sections of the code.
So if I go back to edit after submitting html code - I have to hunt around in the compact code that is generated by the editor - and have no way of leaving hint comments to locate something that might need to be edited. As it is the editor recognizes comment tags <!-- --> by indicating them in green when I paste them in - but again only to be lost after submission - but it seems the editor could be tweaked to keep those tags and the color - which make it easy to find sections of code marked by them.
I am not sure how many other users utilize the html markup and editor function - or how many might use it as heavily as I do.
But if this is possible - and relatively easy to implement - it would be a great help and a wonderful addition for a near future update.

Thanks for listening