Thanks for the replies!
@Quoth yeah it can get pretty hot here and also muggy on the cooler days, but I just don't like going out to sit indoors in the summer
particularly after covid bankrupted almost everything with spacious indoor seating. I rarely expose Kindle to direct sunlight, I usually tend to sit somewhere in the shade first. I can't be that particular with the phone, obviously, but as said, it tends to heat up over time even in conditions acceptable to ereaders. I buy a flagship and keep it going for several years until it's completely EOL, so I'm unwilling to chalk it up to shoddy manufacturing.
@rcentros, yes I checked the manual too. As far as I understood Shine 5 is a Kobo Clara BW clone and Clara BW doesn't do landscape, which is a must for me. It seems logical Kobo would do that to help sell a 7" b/w ereader, but they don't have any...
I tried to look for a used Libra (which would be the source of Vision 6), but the usual website in my country is absolutely dead. Apart from the Kindles, there's a single person selling an Ellipse 2E for 500€ (go figure). Not too surprising since it's a small country and local ereader pickings are slim (we only got Kobo this year). I tend to order electronics from bigger EU countries and have it reshipped.
IIRC, Pocketbook Verse lineup keeps night mode on in the menus? I've noticed Clara BW doesn't. Having it stay on would be nice.
On the whole, Tolino Vision 6 or Vision Color seem to be good buys and Pocketbook Verse Pro and Verse Pro Color too. Interestingly, they're all almost the same price.