It appears that the manufacturers themselves supply the funding for SFI (started with SEMA). Is the fox guarding the hen house?

Note the phrasing in the negative of 16.1:

"2.12 The useful life of the webbing in the straps shall not exceed two years and they must be replaced at or before that time. Only the original manufacturer can re-web an assembly prior to re-certifying."

Why not: "the useful life of the webbing shall be not less than x years....."

Check the Disclaimer:

"14.0 STATEMENT OF LIMITATIONS
Testing procedures and/or standards contained in this specification are intended for use only as a guide in determining compliance with the minimum performance requirements as defined herein. The granting and assignment of the "This Manufacturer Certifies That This
Product Meets SFI Specification 16. 1" logo/designation is in no way an endorsement or certification of product performance or reliability by SFI. SFI, its officers, directors and/or members assume no responsibility, legal or otherwise, for failure or malfunctions of a product under this program."

SAE could propound an aftermarket belt or racing standard. They have a number of seat belt standards already. No reason NHRA couldn't petition and adopt that instead....