Hacks Kindle with PocketBook Firmware?

[sarcastic.guru]

Hey guys,
Proud owner of two Kindle devices so far (first the Basic 2016, then upgraded to Paperwhite 2015). The one and only thing I don't like about them is the continuing effort of Amazon to behave like Apple, in means that it closes more and more its ecosystem and keeps adding small inconveniences for side-loaders. Let's take for example the last issue of disappearing covers if a book does not match with a purchase from the store.

And I perfectly know that Calibre has now fixed that. But all these little issues are somehow discouraging. Or let's take the inability to sync with the cloud a book that can use custom fonts and show its cover at the same time.

Surviving through all that "hell of small things" myself, I decided to buy a PocketBook as a present to a friend and set it up just to test the system. Oh, the pleasure of a device that is simply... just open and user-friendly oriented.

So here comes my question: is there any way to wipe my Kindle to a level where it's only a blank device with no OS on it and then put a running PocketBook firmware on it? Or, let's say just use the Kindle hardware, installing PocketBook software on it? I didn't find anyone who described an attempt to do it anywhere on the legal Web, so I decided to ask around. Thanks,