Looks fine to me. I tried it without magnets and I’m fine with it. Yes, sags a lot, but I don’t care.
My car is usually in the garage and work from home. And I have not run the car A/B with and without so I don’t know. Seen other videos that it helped significantly.
I did not use the extra layer.
I mainly got it to help quiet the cabin down. I think it works. I had one in Model 3 too. Makes harsh noises softer.
I never take it out and never plan to.