Looking for privacy on an E-ink reader

Airplane mode is regulated by law in the EU, China, etc… it turns of all radio signals like WiFi and bluetooth. So really, just buy any device and once it’s set up put it in Airplane mode and you’re set. No extra software needed. If companies want their phones on airlines, and they do, they need to comply with this. Also, if you want to take a less air tight route, I personally have a kindle with koreader that I’ve blocked internet access to from my router, I then send epubs over with the LocalSend plugin wirelessly over my local network.