If the ribs and cavities of TF's backstrap are machined identical to the PPQ's, then it will not clear the circular protrustion at the rear of the P99's grip:
What's odd is that they didn't make it out of the same stuff as the polymer frame, and that when they decided to use a different material they apparently didn't spend any time considering the durability of that material.Ozone is great at destroying rubber type Polymers. Electric motors (such as fan motors) will destroy nearby rubber products in a few years.
This is common knowledge in the SCUBA gear industry. The topic was discussed in my SCUBA certification class over 35 years ago.
Want to destroy a $1k BCD, or rubber fin straps? Store them in a garage with a Washer/Drier that gets used regularly. Or in the closet of a room with a ceiling fan that runs during the summer months.
"Ozonation of Polymers" Ozonation of Polymers