I get what you're saying. I had it tuned like that to begin with, that's how I normally tune. I did it this way because the guy from 6l80tuning.com said to try it this way to get reported torque up using maf instead of the torque tables. Neither way works to keep the converter locked though. I'm leaning towards this converter isn't quite right for this setup. The customer has a CTS-V converter, he'll probably end up putting that in.
A buddy of mine also has a G8 with a 416, LSA blower, and CTS-V converter. I drove that this morning and logged it (still tuned in a manner you suggested) and it unlocks the converter on accel as well. I literally copied the TCC tables for the CTS-V I posted the logs for (that doesn't unlock on accel) and it didn't make a difference, still commands to 0. So, why would the CTS-V not unlock on accel? Same with your Vette, if it stays locked on accel and wot, I would think it has something to do with the OS in the G8 (maybe due to it's intended usage being more geared towards comfort vs a Vette that is performance oriented) and possibly tables we don't have access to.
I attached the old tune that was tuned in the more "normal" way, like I said it didn't change the way the converter acts though