I read your ROPS description, it seems like a solid move. Actually, I do a variation of that, but use the pointer and second fingers, not the thumb and first finger. Basically the same move however. I thought I invented it on my own... shows how much I don't know.
The sun & moon coin set is vastly different than the CSB (copper, silver, and brass transposition). I love the sun & moon coin as well, it's the best copper & silver transposition prop there is, in my opinion. I have a review of the CSB set on my website if you want to take a look at it: