When you probe the rings you have got to make sure that you get all of the rings, the A ring (the one nearest the planet) is normally only a very thin ring, aim the DSS at the planet and slowly move it out away from the planet, when the aim changes to ring fire the probe, it should just illuminate a very thin ring nearest the planet, if it illuminates what looks like all the ring you have hit the B ring, so fire another probe.I must be doing something wrong, or I'm not understanding what the point of "hotspots" are.
A lot of Metallic A rings have got a Metal rich B ring surrounding them, Both can have Painite and Platinum hotspots in but only the Metallic will have laser minable rocks.