Mentioning this in case anyone else is reading this thread. The holes on the Silver 2 shifters don’t quite line up with the cable guides in the Velo Orange mounts - the cables will go through but it puts a tiny kink in them. We had them on my son’s Platy initially for a very short time and it started to fray the cables.
I have had success with Sunrace thumbies or bar ends mounted on the Velo Orange thumb mounts. As they come with road bar diameter shims I have them on my Cheviot mounted on some Albastache bars, just either side of the handlebar sleeve, on the underside of the bar