This may be of limited interest, but:
I have about seven POV characters in my first book and have just used Scrivener to compile all the POVs for one of the characters so I can send it to my Kindle to refresh my memory of her storyline and make notes on deletions/additions (I love Scrivener for this, and it's so quick to highlight in a Kindle certain things).
After sending it to my Kindle, I got this email from Amazon Kindle Support:
I have about seven POV characters in my first book and have just used Scrivener to compile all the POVs for one of the characters so I can send it to my Kindle to refresh my memory of her storyline and make notes on deletions/additions (I love Scrivener for this, and it's so quick to highlight in a Kindle certain things).
After sending it to my Kindle, I got this email from Amazon Kindle Support:
Thank you for using the Send to Kindle service to send personal documents to your Kindle library. We noticed that the following document(s), sent by you at 09:50 PM on Tue, Sep 06, 2022 GMT are in MOBI (.mobi, .azw) formats:
* Marville's stuff.mobi
We wanted to let you know that starting August 2022, you’ll no longer be able to send MOBI (.mobi, .azw) files to your Kindle library. Any MOBI files that are already in your library will not be affected by this change. MOBI is an older file format and won’t support the newest Kindle features for documents. Any existing MOBI files that you want to read with our most up-to-date features for documents will need to be re-sent in a compatible format.
Compatible formats now include EPUB (.epub), which you can send to your library using your Send to Kindle email address. We’ll also be adding EPUB support to the free Kindle app for iOS and Android devices and the Send to Kindle desktop app for PC and Mac.
If you have any questions, please visit our help page or contact our Customer Service team.
Regards,
Amazon Kindle Support