Theres a thread on 6speed in the 996TT/GT2 section about someone asking a similar question on a stock TT motor. Now you got to take into consideration that obviously it's a different motor altogether & that its boosted, but it gives you a general idea of how Porsche's DME acts.
What was stated by the tuner/softronic manipulator is that these motors can be filled with 87 octane and not blow up on a completely stock car / unmolested DME. At the same token, when race gas was used the DME actually put on 30-40 more horsepower then stock. What this means is that the DME's are advanced enough to know that something is either going really wrong and cut back on ignition timing or it'll go more advanced when it's recognizes that knock isn't happening and goes the other way. BTW, if you want to give it a shot just buy unleaded race gas which goes up to 109 octane ala VP racing MS109.
Although it'll never be this dramatic to our motors being that they are NA, the same algorithm does take shape. So is there a gain? just slightly if anything. All the guys like softronic/giac/ etc etc do is manipulate the ignition timing. Porsche puts X amount of advance with a safety variance in mind, all the tuners do is bump it up a bit then find a way to charge people $1,000+ . Must be nice