I didn't seem to be last I checked -- the older Kindles require the sequence:
;debugOn
~disableScreensaver
;debugOff
while newer ones only require:
~ds
I know that for some ad-supported Kindles it doesn't work unless you pay to remove the ads (for obvious reasons), but if you pay then it will.
But last I checked was a couple of years ago. I'd be very curious if anyone can report it not working. (Also note the command doesn't survive reboot, you have to re-disable after rebooting.)
I don’t follow the space closely, but if you find a Kindle Keyboard (third generation of the product) or earlier, they stopped getting updates ages ago and in fact can no longer use the store (though USB sideloading still works fine). They are all jailbreakable.
As a kiosk-like display, though, they do have that keyboard taking up space.
I only use my Kindle to read outside (at the beach or pool); in the house, my iPad is faster and has a bigger screen. But in the sun, it’s useless. eInk is far superior for that. For the week or two a year that I need one, my 15-ish-year-old Kindle is fine. I travel with a laptop and tons of cables anyway; sideloading just means a few minutes of work after dinner to make sure there’s enough on there to read tomorrow and isn’t much slower than using the internal interface to get books was.
