Trimming OFM Beavertail Backstrap - Production Legal Mod?

[gomerpyle]

Hoping for an answer, but couldn't find one here (maybe google skils are wanting). Is trimming an OFM gen5 Glock backstrap (beavertail backstrap or otherwise) Production legal? it seems that the two following rules do not prohibit it, and that a trimmed OFM beavertail backstrap is consistent with the two rules:

21.4 Grips
Grip modifications such as, but not limited to, undercutting/smoothing the trigger guard, adding or removing finger grooves, or adding stippling, grip tape, or checkering are allowed. Replacement grip panels are allowed provided they do not extend below the butt of the gun to form a make-shift magwell.

22.2 Grips
Non-OFM grip modifications (addition or removal of material) that provide function, such as a beavertail or thumb rest are prohibited.

[Alpha Sierra]

Hoping for an answer, but couldn't find one here (maybe google skils are wanting). Is trimming an OFM gen5 Glock backstrap (beavertail backstrap or otherwise) Production legal? it seems that the two following rules do not prohibit it, and that a trimmed OFM beavertail backstrap is consistent with the two rules:

21.4 Grips
Grip modifications such as, but not limited to, undercutting/smoothing the trigger guard, adding or removing finger grooves, or adding stippling, grip tape, or checkering are allowed. Replacement grip panels are allowed provided they do not extend below the butt of the gun to form a make-shift magwell.

22.2 Grips
Non-OFM grip modifications (addition or removal of material) that provide function, such as a beavertail or thumb rest are prohibited.

The good thing about USPSA is that if the rulebook allows it, you don't need to ask if you can. That's for IDPA.