When the Browning XT first came out around 1996 it became more popular for sporting clays than trap.
I shot one for sporting clays for six years until I switched to a Beretta auto. The 30" is the perfect barrel length because Browning barrels are heavy and the 32" makes the gun nose heavy. The gun will shoot about 60/40 which is perfect for sporting clays.
If you look at the current Krieghoff, Kolar, Blaser, etc. sporting clays guns you will see the straighter stocks-some Monte Carlo-and taller ribs, all similar to the Browning XT.
Actually, it should work out pretty good. Time at the patterning board checking the POI would be time well spent. Most Sporting Clays shooters prefer a lower POI than Trap shooters, usually 50/50 or 60/40...but, that's a matter of preferences.
Two inches of one 12 gauge shotgun barrel will weigh approximately one ounce. Since an O/U has two barrels, that makes two ounces for the extra 2" of length. Now add a little more for the 2" longer top rib and you have more than two ounces.
In addition to the extra 2+ ounces of weight, you are extending the fat muzzle (which contains the choke tubes) two inches farther from the balance point. This increases the moment of inertia and makes it harder to get the barrels moving or to get them stopped if they are already moving.
If you don't think that 2+ additional ounces on the end of your barrels makes a difference, then you should tape a couple of loaded 28 gauge shells or other similar (2 ounce) weight to the muzzle of your gun and swing it around a few times. I guarantee you'll notice a difference.