Yeah, I've seen it that way quite a bit, in fact that was the main way I was trying to use it, but sometimes when there is a big shaped boulder on the side of the shaft sign you go over the big boulder aligning with something in the background. I didn't get the chance to try the straight over the pointed rock across the gap which you had shown a long time ago , over the boulder on other side of gap yet, but this I was thinking it was more rare where I am at. It's possible though there could be more than one alignment off any shaft sign or at least a couple ways they used them on a map.