Luke,
Can you reconsider the MIPS32 and Ingenic? The Creator C120 and C140 from Imagination use a very similar chip - the video chip has some non-free drivers but there are alos Libre drivers, I believe.
https://imgtec.com/contact-us/ should have contact details.
It is certainly feasible to install Debian on this: no other distribution is supporting this chipset any more, I believe, though I could be wrong about OpenWRT supporting some models of MIPS chips embedded in routers etc.
[No connection or endersement of Imagination here other than as a satisfied Kickstarter customer for the C120 and awaiting the C140 arrival as a Kickstarter backer - due any day now]
All the very best,
AndyC