Mercedes allows steering wheel corrections while actively engaged in their lane keep assist system. Necessary since it’s so horribly bad.
I’m a trained mechanical engineer and in the course of that schooling took several human factors courses, which discuss how designs can enhace or hinder safety and ease of use based on human psychology and behavior.
From a human factors perspective, a system that lets you steer without disengaging has a significant risk and danger to it. You lose a lack of clarity about whether the system is engaged and whether you or the vehicle is in control.
In the USAF and indeed in all flying, it’s referred to as maintaining positive control. To take over control of an aircraft with two pilots on board there is a readback of control transfer:
“I’ve got the jet.”
“Roger, you have the jet.”
This isn’t for kicks. It’s proven to enhance safety because there have been accidents where both pilots thought the other was flying and the jet just barreled right into the ground.
With ambiguity about whether the system is engaged or not, there would be accidents in which the driver thought the system was engaged but it wasn’t, and the car drifts right into a tree.
I doubt Tesla will go this route.