the token data could also potentially expose limited information about anyone who had exchanged emails
I assume if the gov can use the digital post office argument on push notifications they can also do that on your email directly? So it wouldn’t change anything if you have notifications for that right?
IMO the one you already have. I use my phones Books app. It can read epubs and you can buy books in the store too. Also has settings for different colors, I really like the white on black dark mode theme.