[Quoth]

I have the elipsa and the Sage.
Even on the Elipsa (10.3") I had to install KOReader to have automargin cropping. If you are using Magazine scans, Letter or A4 technical PDFs and book PDFs for larger technical books, then the Elipsa is a minimum.

I can use instruction book PDFs on the Sage (and even on Kobo H2O original or Libra original), but a 215mm x 140mm McGraw-Hill textbook in PDF has print too small even with the margin cropped off (188mm x 110mm. approx).

Android in some ways is worse now than 10 years ago. It's optimised for LCD/OLED phones and even Android 11 on 10" tablet is little improvement on Android 6. I have the Android based Boyue Mars (7.8") and it's Android 8, but a non-standard better GUI than 8 or 10 or 11 on my Tablets. However for actual ebooks it's poorer than a Kindle or a Kobo. I use the stock reader for PDFs (as it does crop) but KOReader for epubs.

On the Elipsa I only use KOreader for PDFs, I find the native epub and kepub and "library" integration far better than KOReader.

I bought a 9.7" Kindle DXG for PDFs on Sale from Amazon once. Worst ereader I ever bought. The 167 dpi and 9.7" made it useless for old magazines or textbooks. Only smaller size PDF scans from novels, pre-cropped and brightened with ImageMagick could be used.

Summary
Reading novels and instruction leaflet PDFs: Libra2 or Sage, I use Libra for proofing & Sage for recreational reading. KOReader not needed.

Datasheets, Textbooks, scans of old Magazines, A4/Letter PDFs: Elipsa, but use the one-click install of extra menu & KOReader for PDFs to have good autocrop of margins. No jailbreak or other patches needed.