All holsters will wear the finish of your blue gun; if you compete, and practice, your finish will show it. If that is a concern with this gun and you consider it a "collectable" you probably need to locate another gun. Save this one for a BBQ gun.
Not many of us abuse our equipment, but missed reloads, shells hung under extractors, starting positions with guns on raggedy surfaces, banging a prop as you walk by when pasting, whacking a port under recoil or when misjudging distances (or just plain missing the port), trying to reload while simultaneously holding some kind of prop (bucket, grenade, etc) will all leave marks on the gun. Just like any other kind of tool or sporting equipment, at the end of the season it will show if it sat in the box at home or got used.
Understand - the gun is older but not a safe queen. It was a Police issued gun and has some bluing wear. I guess what I'm really asking is will the Kydex wear the finish faster then either leather or the Safariland lined holster?
Thanks,
Jeff