Bezel mode switching - long term reliability?

So I was applying some grease to the threads of my T10C last night and examining the contact ring on the PCB that touches the body to get you into high-output mode. I've had this light for about a week, and the contact ring has a few noticable grooves in it that appear to be from either the top surface of the body, or perhaps some grit that was left over from machining.

My question is, has anyone ever had the contact ring on this type of light completely wear out, preventing you from entering high mode? I'm not particularly concerned about it since I don't carry a light for more than six months anyway, but it seems like a failure point if someone was to use the same light for many years.

Additionally, I think if this DID happen, you might be able to repair it with a PCB trace pen. You'd have to be careful with the application of it, but it might be a viable option if you want to keep your light in service?

If you're worried about it, one technique while you still have some trace left is just to add on some solder.