As far as I know A600gs, and probably A1200ng as well uses Amiberry-lite which is still at version 5.x
Also I suspect they use the 32 bit version, and it looks looks like Amiberry 8 is targeted at 64 bit only.
You are correct that we use the amiberryy-lite fork, with our own modifications, but we certainly use a 64 bit build, why would we not on 64bit hardware.