I discovered the trick because I was scratching my head over where 3 more rings come from. I first figured they were on another route, then thought they might be in one of the breakable objects under the floor for some reason, proceeding unto the top route with the four/five collapsing floors with rings spaced between them because it seemed like there were rings randomly appearing there for some reason, which brought me to discover that you could use that particular crusher to an advantage. I shared because one, it's a pretty large lead in a game that is not named Sonic Rush and I think it needs an explaination, and two, people don't seem to think I can discover my own tricks. :[ I'm not quite sure why, but oh well.
Also, I must agree with you Crow, Star Light 1 and 3 are probably the hardest RA's in the game, or at the very least, the most annoying. I'll say that Star Light 3 is probably the worse offender though X(