I second this as well! I noticed my "read" books aren't matching with my other reading trackers anymore and I have too many books to go through individually

I would love this as well. I have a formidable difference between my Goodreads books read and my THE STORYGRAPH books read. I know some of that is rereads--which I don't do a lot. I would also mention that I have found several books showing that I have reread them which I have not so that may factor in as well.

I'm not sure if this has been developed yet, but I would love to be able to combine all the editions of the same book on my TBR as one title/entry. Similarly if I have read the audiobook version of a title, if I own the paperback or digital edition, that should automatically update to read as well.

Yes to this! I often mark a book to read and later come back and select the actual edition I'm reading like audio but had previously marked the paperback as too read and forgot. Would be nice to find duplicates on your TBR but also to make sure it looks at your read titles as well.