Cranks but no start

[twarr1]

2007 E70 3.0, cranks but doesn’t start.
History - for the last few months the car would ‘hiccup’ occasionally especially when hot. Then, when cold, < 32F, the engine wouldn’t accelerate after starting for about 30 seconds, then it would smooth out and ran fine. Codes retrieved were MAP sensor and the constant P0012.
A few days ago in a very cold morning I started the car and it ran very rough for a few seconds and died. Wouldn’t restart at all. It cranks over fine but doesn’t seem to even try to start. The only thing I noticed the previous time I started it to let it warm up, there seemed to be a vibration in the exhaust. I wrote it off as maybe snow packed under the car along with the very strong wind.
I charged the battery, replaced the MAP sensor and still nothing. Opened INPA and of course there were about 15 codes from running the battery down to 8 volts. I cleared the codes, and tried starting - just cranked. No new codes. Crankshaft sensor shows ~ 200 rpm while cranking. VANOS actual and set points match. Fuel pump runs. I also ran ISTA-D and it showed a 2AB4 DME checksum error. Cleared it and hasn’t come back.
Any ideas? Did it jump time? I would think if it did it would crank fast due to no compression. Did the catalytic converter collapse and plug the exhaust? Is that even plausible? Do I need to reset the EWS/DME code? I’m charging the battery again now and plan to check all the fuses including the fusible links on the battery, but really I’m at a loss how to proceed.
Sorry for the long post, I’m mostly writing this to document this fiasco. Any wisdom or ideas are appreciated! Thanks ��