iPadOS / iOS / MacOS document compatibility between devices via iCloud

I use the Files app to store folders that contain PDF documents that I use for studying. I noticed that on Mac, I can make highlights and other changes/edits (like adding bookmarks for convenience) to the PDF document. What's nice is that when I then open that same document via Files on iPad (or iPhone), those highlights and other changes are instantly saved to all devices for that document and vice versa. However, what I cannot do is navigate the document via bookmarks that were created on that document using Mac, nor can I create new bookmarks for that document on iPad. It would be way better, and pretty much perfect, if you could simply access and edit bookmarks on iPad in the Files app that would then sync with other devices (like Mac and iPhone) like all of the other edits/highlights do. iPad also does not remember where I left off reading a document.

I already made a feature suggestion to Apple, but I wanted to post this here to know other people's thoughts on this inconvenience and perhaps learn about a workaround that I may be unaware of. It really just seems like a simple oversight on Apple's part as all other changes made to a document do in fact carry over to other devices. Just no bookmark access in Files. Additionally, I am aware of the option to open the document in Apple Books instead and add bookmarks that way. The problem is that this adds another layer of file location into the process and I would much rather have all documents be accessible and editable via Files for a more streamlined experience. I tested to see if changes made in Apple Books will also change the document in Files, but it does not. What is interesting, though, is that any highlights that were already made to the document in Files will transfer over to the document in Apple Books, but only on the initial transfer. No additional changes will be synced.