Thanks for reminding me what you were going to do. I remembered the KRX muffler but didn’t recall the 3 to 2 1/2” setup.There is certainly the possibility that Alba's tune could be fueled well enough for my exhaust setup, but unfortunately he (Nate himself) did NOT seem to be so sure and he suggested that it could also very well just be a starting point. While I am sure the Alba tune would be a better place to start than the OE GYTR tune fueling wise; that GYTR collector, pipe, even with the Trinity exhaust is quite small/restrictive vs. what I am looking to do and so I likely will require more fueling even yet. But yes if you are using ANY aftermarket "slip-on" this means that you are using the standard GYTR collector and pipe, while only changing the muffler at that point, and this is the difference.
My exhaust setup is a cast SS Garrett 5-bolt flange to 3" v-band, 3" tapering to 2.5" at the muffler, then using the Trinity Stage 5 KRX muffler which is 2.5" ID (with yxz frame mount).