When do you need new hardware?
Not all solar DNR jobs require new hardware but there are times when they do. If your DNR provider has never asked you about replace hardware then you should have a talk.
The primary reason you would need to get new hardware is if the system was installed using an e-Curb or similar product. The L-Foot is bolted to the rafter and then a mold is placed around it. Once in place an epoxy is poured into the mold and hardens. It is impossible to reuse this type of standoff is you need to replace the roof because the epoxy is hardened and the lag bolts are buried. Very effective for leak prevention but designed to never be replaced. They gotta go!