If you happen to run over something in the road, it won't tear up the underside of the engine bay, oem belly pan, and potentially crack the cast aluminum oil pan if you hit something big enough.
I’ve got an aluminum skid plate, trans plate and rear bumper plate. There are pros and cons
OP, I suggest you separate it in 2 parts. It’s a pain installing an aluminum pan when solo and you’re just working on jack stands. Also if it gets warped after hitting something it could start to drag. A few years back I was driving to out of state and the BMW tech that worked on the car didn’t properly tighten the front bolts. Middle of no where the front starts dragging and car is too low to get any tool under to resecure.
Is your design missing the oil drain access?
Rattling / vibrations if it’s touching anything. I have sound deadner on it to prevent that now but previously if I over tightened it anywhere the thing would make noise.
The extra bit of weight will cause securing issues when using stock mounting points. I have those push button release bolts on mine now but use to use new hardware every damn time I re secured it. Can be aggravating.
Ideally you want something that can seal the bottom of the car but CAN break away unlike aluminum.
The advantage for me was allowing me to add some strategically placed aero designs. The absolute best place to seal is the rear bumper to the diff. It’s a parachute on 335i’s. The design of the *M3 exhaust is to eliminate that