you have to harvest the bud early to make it a light rosin. as far as crcing it… it definitely wouldn’t be rosin anymore and that ruins the purpose of even making rosin but you could dissolve it in pentane and run it through crc like you do with chromotography or you could dissolve it in tane in a closed loop system then flush that through a crc.
only time i would do that is if the rosin came back with pesticides or mold. your best option would be to decarb it and make solventless edibles