On Friday evening, prior to the FNRttC, I replaced the mount and cleat of my Exposure Race light, because it was so rattly it would no longer hold the light securely. I experimented, and the old cleat rattled on the new mount, and the new cleat rattled on the old mount, I had to replace both of them, which was annoying (and more expensive).
The old mount seems OK with the slightly bulkier plastic cleat of the Joystick, but I don't generally want a mount just for the Joystick (which is a combination spare light and handy torch for mechanicals on the FNRttC and similar night rides).
I wonder if replacing the cleat before it's too worn will extend the life of the mount, like replacing a chain to save wear on the cassette?
That mount has done around 8000 miles, since I virtually always have the light on my bike, which isn't too bad, but could be better. You don't expect a metal light mount to wear out.