I've got the same Ergon's, except they're the grip shift variant.

The issue isn't mounting a bar end mirror with them. It's getting the bar end to be usuable with a mirror mounted. By the time I set the mirror up to where I can use it properly, then there is no good angle for my hand and wrist while using the bar end. I've even tried installing the mirror in the bar end itself (trick I picked up here on BF somewhere), but I couldn't get a good field of view- save for my arm and gut.