As a disclaimer, I mainly do Gen III conversions – but have a conversion similar to yours booked for later in the year, so I'm trying to get up to speed on E38 / T43 swaps.
I took a quick look at your VATS parameters G1204 - G1216.
From the research I’ve done, there a couple of possible issues associated with your “no start” condition.
You are running ECM OS12614088 - this particular OS in a transplant seems to require a VATS patch + VATS Type 2 + crank relay current. I’m assuming your tuner applied the patch, as G1210 is properly set to Type 2. You will need to apply power to the crank / starter relay (from ECM) in your wiring harness.
After this, if the engine still fails to start, some of your VATS parameters are not consistent with what others have successfully used.
Try these changes only if the engine fails to start after applying power to the wiring harness as described above …..
G1205 – Yes
G1208 – Enabled
G1215 – 600
G1216 – Yes
Regards,
Taz