Firstly, I'm no expert at this sort of stuff. Take this as a guide, but don't
quote me.
In terms of making a computer card from the PocketCHIP, I don't think you're
going to be able to reach EOMA68 compatibility. The devices use an Allwinner
R8 processor (see http://docs.getchip.com/chip.html). The fact that it didn't
make the list for the initial EOMA68 card, despite being from the company
whose processor was eventually chosen, suggests there was an issue. I can't
tell you for certain what it is (likely something to do with video
resolution), but the datasheet is linked from the page mentioned above.
As for freedom, the bootloader/initialisation stuff is good. The processor is
probably decent, although I'm not sure if the R8 can run fully free, but the
wifi card is concerning. I can't find the specs (they're probably nestled
somewhere in the GitHub tree), so it's probably proprietary stuff given the
severe lack of free cards.
If you really want something free, I'd suggest working with the BeagleBone
Black instead. That's known to run fine without proprietary software. You'd
have to check that it has the core features to reach EOMA68 compatibility,
although the processor is more promising (a Texas Instruments one- I believe
the issue with those was related to customs, not specs).