How often are you finding the core rocks in the belt clusters?
I've only found 1 out of a dozen or so clusters so far, and it wasn't immediately visible when dropping in. There was about a 30-60 second lag before the roid glowed. That was after several pulses. I've noticed the same in some other clusters with a delay in the PWS revealing surface/sub-surface rocks. I'm wondering if I'm hitting some weird lag bug, or the cores in clusters are a lot rarer than I expected. (or i'm just really unlucky)
It seems to be about one deep 'roid per system of clusters. Sometimes, get lucky and find it quickly, other times .... ughh !
It feels more satisfying to scan the rings, and once you know what you are looking for, can waste fewer prospector limpets there.