a fantastic idea but a 4.2 inch screen is way too tiny for most people (including me) i feel like

Diptyx is an ESP32-based, open-source ereader. https://diptyx.dev/

Features

Processor: ESP32-S3-N16R8
Displays: 2× 5.83'' 648×480 e-ink black & white displays
Storage: 2GB SD card, user-replaceable
Batteries: 2× 1500mAh Li-Po batteries
Dimensions (closed): 120×150×14 mm (4.7×5.9×0.6 in)
Dimensions (opened): 226×150×14 mm (8.9×5.9×0.6 in)
Weight: 300 g (10.5oz)
Connector: USB-C for charging and mass storage

Seems like all the FOSS alternatives have serious drawbacks. I read on 8inch and the only reason i wouldn't want to go larger is weight, i want to be able to read one handed. Both 4.7 and 5.8 seem just... Way too small and too small. I love the idea of a dualscreen, its playful and honors the classic book form factor, but for my personal reading I can't imagine enjoying that. Still very interested in folks review and use of these, and if they might spur even more FOSS alternatives or forks of these designs.

My 8inch non-FOSS eReader is very cool, but i'd rather never buy locked software or hardware ever again, so fingers crossed that this is all just the start of something way bigger :)

I want to try the Amazon Oasis because it has uneven mass distribution and should be perfect for one-handed usage. I think it is brilliant and should be the default design. None of the competitors implement this.