Must be either quality control or driving style. Any other ideas?

Do you just hold full throttle and never let go?

No, but I do have it past 1/2 stick most of the time with multiple bursts of WOT. Generally takes me 20 min to use ~5500 mAh. Lots of high speed runs around the field, back and forth on a gravel drive, around a dirt track, and sometimes in a hilly retention area. No hard jerky starts or backflips, but I do enjoy the occasional wheelie. Have the punch set around 50 percent, and start power on lowest setting. Like I've stated before, the problem disappeared with the oil, but it is strange to me that some have been able to run the same gears dry without issue.

Could be the actual distance driven. Someone who mainly bashes on weekends, would put a small fraction of the mileage on their truck compared to what I subject mine to. It's not the bigger motor either because I started going through gears since the beginning; probably granaded the first set within the first 2 months.