Without a doubt, I can say that the Gulf Yachting Association (GYA) would absolutely penalize an a-sail. They penalize EVERYTHING down here! On the Farr 36 I used to race on, they hit us 3 seconds for replacing the stainless headstay with a PBO one. Also, they will only allow EITHER asym or sym, but not both on a particular boat.
If I had an endless budget, I would like to get some sort of "luff supported reaching spinnaker" (i.e. blast reacher)
Can't hurt to dream