Koreader is well supported and has all the features you mention.
I have been using it like this for a while and it is absolutely bliss to be able to view a catalogue of my inboxed articles on my kindle, with annotation (exports of which are also supported in KOReader).
That said, I do most of my reading on a Books Palma 2 now. Smaller, so it fits better in a smaller bag or a pocket. And does have physical buttons.
I've had my Kobo Clara HD for almost 8 years and I still use it daily with KOReader. It's so easy to install KOReader and it's really repairable. I replaced the SD card at one point, and another time I thought it was broken or needed a new battery but came back to life after reseating cables.
Before that I had a kindle and you had to jump through a lot of hoops to install KOreader, and I remember you had to be careful not to upgrade the firmware so it could be jailbroken.
Like I said I've had the Kobo for 8 years, so I hope this is still the case.
Calibre web support, opds catalogue, wallabag, ssh. And it supports so many file formats.
I'd imagine the built in reader has improved a lot over the years, but at the time reading technical pdfs on it was not feasible. KOReader allowed me to rotate to landscape and reflow the pdf text.
I almost got the Clara BW for Christmas, I thought my Clara HD was dead, wasn't sure if it was the battery or screen but it was failing to properly clear and update the screen. Someone actually bought the BW for me but I ended up returning it after I managed to recover the Clara HD.
I was kind of looking forward to the waterproofing, but seems my old one is not yet ready to give up.
I was a happy Oasis user until last year when I used a new Kindle and saw how much faster they’ve gotten. That started a very frustrating search for a kindle replacement. I ordered and returned many units before settling on the Kobo Libra Color. I didn’t want color, but I don’t notice the lower resolution now unless I’m using it side-by-side with a B&W screen. I do miss whisper sync, which I’d occasionally use to read a few pages on my phone. The Instapaper integration is awesome— I used to pay for KTool to accomplish something similar.
1. Self host readdeck, add articles to it
2. Have an ebook generated automatically each article saved/day/week/etc
3. Have the ebook be automatically pushed to your jailbroken kindle with KOReader
New side project unlocked, thanks!
This gives you full access to upload whatever ebook you want (SSH, WebDav, Syncthing, ...) and it can fetch RSS feeds (i use it with FreshRSS.)
PS. The (very old) Kindle Oasis is still the best device there is to read on in my opion. Which is crazy, since it was released from 2016-2019...
It has 2 phyisical buttons to turn the page, and an ambient light sensor to auto adjust the brightness, and a 300 PPI display.
I'm still "waiting" for a better / equal device to be released.
[1] https://kindlemodding.org/kindle-models.html
[2] https://github.com/koreader/koreader