Shield or blanket

According to the NHRA rulebook (2021), cars running 9.99 or 135 mph or faster w/ an auto trans, must use a flexplate shield that meets SFI spec 30.1.

I don't imagine blanket meet 30.1 since they're covered by SFI spec 4.1. Here's a link to the two SFI specs:

https://www.sfifoundation.com/wp-content/pdfs/specs/Spec_30.1_061799.pdf
https://www.sfifoundation.com/wp-content/pdfs/specs/Spec_4.1_032713.pdf