I'm not sure if this theory holds any water, but one guy who owned a body shop that did a lot of aftermarket work says that carbon fiber continues to cure in direct sunlight for a while. He suggested rocking bare carbon fiber for a few months, then getting it painted, it would have better results.
depending on epoxy used it could take up to 3 days to truly reach its full cure (if they got there mixture right) after that a wet sand with a 600 grit is fine if you are wanting to do a clear coat or 2 part mix paint. Ive been making carbon parts for the past few months and i am speaking from my own experience anyone who says the epoxy takes a long time to cure is either getting there mixture wrong or using the wrong stuff..
if they used Prepreg carbon (dry carbon setups) then it should be fully cured after getting out of the oven and cooling down.
the VIS stuff you have is cured by now by the time they made it and it reached you then it should be ready for prep and sand so you can paint it..
not sure if VIS clear coats there parts or uses just an epoxy that is uv resistant plus a epoxy clear coat on top.. that something you would have to ask them.. people who make parts have different methods so its good to know what was used on how it and how it was made..