tbf there is not really a good solution to the ‘ephemeral aspect’ problem
the only way to truly not sync metadata to or btwn servers at all is to use a p2p model, in which you cant send anything if one of the parties is offline
simplex might be a bit better in this regard, but still relies on servers for syncing. at least it doesnt extensively replicate metadata like matrix does though
so it depends on your threat model whether this is a compromise or not
used kindle paperwhite, check firmware version to ensure jailbreak jailbreak, install koreader
use calibre to manage library, source books from uh. the seas
amazon devices have quite good screens for the price
however, if you are reading comics, you should get a bigger screen probably a tablet, look into boox and meebook, both are android based
i would not recommend color screens rn, they still have significantly lower contrast and resolution and refresh is slow af
sure that is how pop3 does it
but metadata is still replicated to the server, so this does not solve the metadata replication issue
even if you dont explicitly store metadata or encrypt it in some way, the server still necessarily knows stuff like timestamps of when the messages are sent for example.
sure, you can delete it later, but you also have to trust the server to actually do that, and there is no way to guarantee this in any protocol