I have a couple of those Safailand kydex holsters (thigh rigs) with the thumb release button sort of behind the grip/frame where your thumb automatically hits it and releases the pistol as you grab the grip.
I really like them except for one thing They are wearing the finish off the slide of my M&P 9MM and my P07 9MM.
The M&P is the factory finish. Not sure how durable it should be but I've never had the finish wear off like that on other M&Ps in spite of carrying them (different holsters) yeas ago.
The P07 slide was nitrided after the cut for the red dot and new back up rear sight was made. I had that treatment done because everyone said it was such a tough long lasting treatment for the surface of hard use guns. Daggone cerakote on my P07 .40 lasted years longer before it finally started to show wear through marks.
What I did was get some really thin leather pieces, some gorilla spray on glue (similar to the stuff used for headliner material installation on the backer boards of the head liners in cars/trucks).
I took the holster off the rig, removed the screws (opens up like a clamshell) and thoroughly cleaned it out with alcohol and a lint free cloth. Let it dry (doesn't take long).
I sprayed the glue on the holster and the leather (followed the instructions for wait time, etc. before putting the to sprayed surfaces together) and worked my way from one side of the holster, across the top/front and back around the other side in three steps waiting between so I could insure I was getting that leather pushed into the angles/recesses and letting it dry before moving to the next section.
Let it sit for a bit and put the
thumb release mechanism back in, closed the holster up, put the screws in it and let it sit with the M&P in it for a bit. Then trimmed the excess leather off the top and bottom. Waiting on an Xacto knife hoppy kit to finish neatly trimming the leather before putting the holster back into daily use.
If it works I'll do the P07 holster (and take pictures next time.)
I have some other Safariland holsters with a similar lining inside to protect the finish of the slide (FNS and XD holsters) and they work great. Figured I'd try it with these holsters to see if I could make it work.
Edited - it's not a "thumb" release. It's contacted my the middle finger of the hand grabbing the pistol grip to remove the pistol from the holster. Works great.
Edited to add - picture of the M&P holster with the leather trimmed with that very sharp Xacto knife (nope, did not cut myself on this one. Blade is so sharp very little force is used to cut. It's actually harder to guide the knife blade than to cut the leather with it.