My tests were, thankfully, set up so that if you are getting an additional attack of a different Profile the cost is 1/4 A-Cost, not 1/3rd.
That's fortunate and (actually) intentional when I set the test up. One of the reason that JAGS uses so many powers of 2 and numbers divisible by 2 is because it makes fractions simpler. Why would I then go and factor the balance testing for 1/3rd?
I was like "Did I really do that?"
No, I didn't--I just wrote it wrong in the last post.
Here's an example scenario: A character has spent 16 AP on powerful fists (Profile: Standard) and wants Dragon's Breath (Profile: Periodic) as well. For 4 AP they can get 16 AP worth of Dragon's Breath (a different profile: Periodic). If they then want a smashing tail with a Profile of Standard, they can get it for 1 AP at 16 AP level because they already have a Standard attack.