Put the FulSac on my 2011 SERGU except didn't pay for the tuner. My bike runs just fine and saved about & 475. I was told that the computer has enough memory and bike is running good.
It's not about whether the "computer" (ECM) has "memory" (it doesn't in the traditional computer lingo way), but whether the standard, stock MAP can adapt to changes to the intake/exhaust flow via the input from the narrow band O2 sensors in the header pipes. What you have stock in the ECM is a MAP that is already on the ragged edge of being too lean (read: extremely hot running engine). Even if the ECM can adapt to some changes, it still makes the air/fuel ratio very, very lean because it's always going to try and get the A/F to the stock configuration.
If you only change the baffles in the stock mufflers, and do nothing to the head pipe, it can probably cope with the change. But, IMO, if you change the header to another type/brand, OR you remove the Cat in the stock header and then put it back on, the bike needs more fuel, and the only way to do that is to change the MAP in the ECM, or fool it into thinking it's running too lean, so it adds more fuel.