hmm, you got me thinking...
from various discussions here on TMC, and IIRC comments directly from Tesla, my understanding is that the reason stationary objects when traveling at considerable speed may not be picked up is that having the software designed to do so currently would result in false positives for the likes of highway overpasses to the point Tesla feels it would be a net reduction in utility to have AP react to this bucket of events.
if this is the reason such events are not currently detected by AP, how about pairing two changes,
1) use the eye tracking to determine when the driver is paying attention to the field of view ahead,
2) have AP respond with a vigorous alert, but not a driving reaction, for this bucket of events only when the eye tracking determines the driver is not looking forward.
in other words, both eliminate potential accident risk of AP having an agressive driving reaction to false positives AND greatly lower the nuisance factor of false positives by only having this aggressive alert go off when eyes are not on the road.
for those using AP as intended (eyes on the road nearly 100% of the time), this alert would almost never go off, so false positive nuisance issue reduced to nil. for those playing loose with AP instructions, lots of eyes off the road time somewhat deterred by more of these false positive agressive alerts (something of a nuisance), and, potentially fatal accidents considerably reduced in the instances when the alert is for a real stationary object ahead (not a false positive) when the driver needs to be alerted (and is) to have their eyes on the road.