Great thread and an Interesting video. I come from an aerospace background and was an aeronautical engineer in my early career. Cars, like planes, like to have controlled crumple zones to help absorb the energy in a crash. This can help reduce the acceleration of your body in the event you were in an accident and the attendant issues like whiplash, internal organ damage, etc. I was once rear-ended by a tow truck towing a large car while I was stopped at a light. The tow truck was doing 65 mph when it impacted my car. Let's just say it wasn't a pretty sight but I lived but not without suffering significant injuries.
My assumption for the aluminum beam is partially to be a sacrificial member in the event of a collision. Aluminum can work well for that and at the same time, it is fairly lightweight. Weight at the end of the car doesn't do anything positive for handling and weight, in general, isn't going to help acceleration or braking either (for the most part). I have been considering a MYP as I might have to tow occasionally.
I am pretty happy I stumbled across this thread while researching towing for the MY. I now need to research how Tesla does the factory hitch but now I know that the Drawtite hitch is a hard pass for me. I have had good luck with their hitches on other vehicles but this design leaves a lot to be desired for me. Removing the aluminum beam and also allowing the hatch area to protrude past the hitch are the only 2 strikes I need to cross it off my list. Realistically just one of those issues would have been enough not to buy it.
To repair that hatch area wouldn't be pretty and it wouldn't take much for someone to back into you to cause some very expensive damage. If the insurance company was petty, they might not cover the damage or maybe not all of it
If I buy a MYP I'll probably just spend the extra money and get the factory hitch. No point in investing in false economy. Anyway, it might work great for some and they may never have an issue with it. It all comes down to your risk tolerance. If I am paying 50-60k for a car, I'll spend the extra few hundred to do it right, or at least better than the aftermarket. If it was just a solid frame car, like an old pickup, you could bolt on most anything and be fine. Or the M3 where there isn't a hitch option in the US so you have to go aftermarket anyway.
Anyway this is a great forum and this thread probably has turned out to be one of the most useful ones in my Tesla research.