The majority of RV spinners are the Van's supplied fiberglass part, makes it tough to polish.

My question would be if Catto is against the idea of anyone polishing their spinner, or if they just don't have a way to do it in house. You can do it yourself, it is just a time consuming and dirty job. Chrome plating is another issue, first it is difficult but not impossible to chrome plate aluminum, and it will be a different look than the polished aluminum on your airframe.
John Clark ATP, CFI
FAA FAAST Team Member
EAA Flight Advisor
RV8 N18U "Sunshine"
KSBA