I'm looking to buy my first e-reader. I plan to buy something used off eBay, like I do when I need a new cellphone. When I get a new phone, the first thing I do is unlock the bootloader and load a custom ROM on it. I thought some e-readers were similar, where you can load a whole custom ROM on the device, and never be forced to use the stock software. It seems, I've gotten that wrong. It seems like most people with a "hacked" e-reader are simply using an app called KOreader, which runs inside the regular factory stock operating system. I guess I'll do that if I have to, but I'm wondering is there any paperwhite e-reader that has a fully custom ROM made for it? I'd like to replace the stock firmware entirely. Any hardware recommendations? Or should I just bite the bullet, get a Kobo Clara HD, and put KOreader on it?
I don't think you really have options that will let you actually completely replace the OS.
There are android options, though. I have two that both support the play store and fdroid, allowing for a lot more flexibility than just KOReader by itself (which is a fine app, but just doesn't support all the ways I use my reader).
I specifically don't want Google in my Android. Are you saying you have e-readers that run a de-Googled Android, which support loading Google Play, etc. assuming the user wants that?
I don't think any of them ship with it. There are requirements to qualify to ship with the play store that include the refresh rate of the screen, and because of how e-ink works, it doesn't qualify. They require you to jump through a couple (minor) hoops to manually activate the play store.