AK Doug is right. If you are using a typical pin sight, you will not see the Biscuit.

Soft vanes like AAE Plastifletch will get wrinkled and distorted when shot through the rest. AAE Speedflyte vanes, Bohning, Duravanes, etc. are no problem at all. They must be glued down well, and have a drop of glue at the front and back of the vane, but that should be the case anyway.