I just took a 5-min video of my testing the "nag" to hold the steering wheel on a flat and straight stretch of road.
Punch line is toward the end of the video! (and written below it, at the end of this post, if you don't feel like watching the whole thing) :biggrin:
My conclusion is as follows:
I personally haven't experienced a timed nag, at least on the roads I've driven and in the weather conditions experienced.
There's lot more testing to be done of course, but that's at least my hunch for now.
The conditions I believe prompt a nag are mostly related to curves in the road (and of course, poor lane markings).