My Lund tune never goes above 12.3 afr. Bama tune hits 12.5. You'd think being that conservative, the #8 issues wouldn't be much of an issue if the timing is kept at near stock specs and the knock sensors are left alone. Which is why I think Lund seems to have to fewest, if any, #8 cars. Bama hasn't had many from what I've read.
When I say lean, I'm not only talking about tuned lean, but also tuned to the edge of lean, then getting bad gas on top of too much timing. But I don't see many people using the AFR's they once where. One of my earlier tunes had a WOT AFR of 13.1. I think I may even have that tune still. But I won't run it due to how much timing they added.