So what do you think is the weakest point on UCE bikes?

[wildbill]

Just checked it out on my 012 model  C5 and for the first time saw this.

[Arizoni]

Yup.  At are a plug alright.

I guess if my 2011 G5 had that plug I would remove it when I was changing oil but from its location I wouldn't expect to see much drain out.

That goes into the crankshaft housing and, as I recall, the little bit of oil that collects in that area gets thrown back into the transmission gears by the crankshaft flywheels.
Beyond that, this area of the crankcase doesn't communicate with the oil reserve.

[squire]

I never noticed that on mine!! Let us know how much oil you get out of there.