ABGX360 has not been updated to support XGD3 backups yet.
0800 rips, are rips made using the 0800 firmware released by C4E that is flashed to your Xbox 360 dvd drive and then used to rip connected to your computer. These rips as long as nothing goes wrong when ripping are the rips that are sought after as they have proper SSV2 info.
Until XGD3 where an 0800 drive is actually needed to even rip the disk, a log of scene groups used "Kreon" firmware, which is a hacked firmware for a standard Samsung computer DVD-ROM drive. This firmware is extremely outdated and cannot rip SSV2 info correctly.
ABGX360 patches these rips with proepr SSV2 info from 0800 rips to make the rip "correct".
There isn't any need for ABGX360 currently for it's number one reason to exisit, since it's not possible to use shitty Kreon drives anymore, which is a good thing. Obviously there's still the problem of if AnyDVD is running in the background or bad disks but it will be released at some point is the assumption, but nobody knows when exactly.