Amazon has just released the 5.19.3 software update for the 11th-generation Kindle, 12th-generation Kindle Paperwhite, Paperwhite Signature Edition, Kindle Colorsoft, and all versions of the Kindle Scribe. There are now. Kindle via USB now supports the latest reading features transferred via USB, including text selection, highlights, notes, and improved navigation. On Kindle Scribe, you can write directly on your PDFs. On Kindle Colorsoft and Kindle Scribe Colorsoft, PDFs display in color.
Not only are there lots of USB changes for editing PDF files, but there are also performance improvements, bug fixes, and other general enhancements.
There are a few other changes not evident in the change log. The dictionary on all Kindles with this new update looks better and more polished. Sideloaded manga files have been broken for a few months, but they are now working again.