I followed up with Odometer Gears, the company that I had originally reported was doing an upgrade for the ATC300, about a month or so back.
To my dismay, according to the representative with whom I spoke this morning, the upgrade is only for the actuator motor, which for the X3 and X5 are a different BMW part number than the x-drive 3 series cars. He assured me that these parts were not interchangable from the SUVs to the cars.
Furthermore, since they are a plastic injection molding shop, they do not have any intention to make a stronger worm/cog interface. Liability reasons- something about 500lb/ft crank torque shys them away
If enough of us here want to fortify the plastic gear, it would take the following:
a) enough demand from the xi community to make a metal (or whatever becomes our material of choice) gear worth it to do a one/limited time run of whichever among the tens of thousands of locations that could do a project like this
b) one of us whose 335xi isn't our daily driver to open up his TC and donate his hardware to send to the business of choice to spec the project out.
So, who cares enough to pay to have this done? This seems like the highest value "peace of mind" modification to the xi community in my humble opinion.
Any other input towards the progress of this discussion is welcome.