Checking a PD shield, is pretty simple. you check the edges, like any other shield. you press on the PD on the front of the shield and make sure it has give, like any other shield. The last step, is the important one. You have to run your hands over the surface and edges of the shield and check for an "Abrasive texture"
Personally, I have a hard on for PD shields. I love them, have been making them and pushing them for 3 years now. But at gates of summer (not this year but the year before.) ... a PD shield came through weapons check and went straight to me. a Unit member from a far flung area with a pretty shield. I ran my hands down the edges, and then had to tell him "No" .. and it is a hurtful thing to tell a person who probably has 30 bucks worth of just PD into his shield.. that his work was for not.
But an unsafe shield, is still and unsafe shield. Regardless of cover.
I also got hit in the face with a shield covered in burlap, and got a road rash on my face that lasted almost 2 weeks. That, was some BS.