IMM76Q could easily have a radio fix in addition to the patent stuff. We all know IMM76K has issues holding 4G connections, especially indoors. Even on a somewhat OK 4G signal, it'll cut back down to 3G. That's something that could be fixed in IMM76Q in addition to the patent fix because I guarantee that radio issue could be fixed in code (especially if it's a kernel problem). If you could fix it in code, you wouldn't need an entire new radio firmware.
Remember on the GSM Galaxy Nexus how IMM76D had all those problems with the cellular connection cutting out entirely until you turned the screen back on? That turned out to be a kernel issue. IMM76I (which fixed it) didn't include a new radio, only a new kernel.
So perhaps the VZW reps are right. Maybe in addition to this including the patent fix, whatever it turns out to be, it will also fix the 3/4G switch issue.