Speeding up the cure
The answer is no - whether you are using a condensation cure (tin catalyst) or an addition cure (platinum catalyst) adding more catalyst will not speed up the cure and will result in poor quality rubber. For condensation cure rubber - any excess (more than 1%) will migrate to the surface and organotin in toxic by injestion. For addition cure - if the correct ratio of base to catalyst is not strictly adhered to then the rubber may not even cure.