Actually the Rules say that you can use a guide rod no heavier than Stainless Steel in SSP
8.2.1.3.4
Recoil spring guide rods and dual spring recoil systems made of material that is no heavier
than stainless steel
I've got a ss guide rod in my glock 34. But I've got the stock one in my range bag just in case
Now where it wouldn't work would be if i used an adapter to make like a gen 4 glock use a ss gen 3 Gide rod setup