If you do get a rifled shotgun barrel, I would think anything shot within average "home-interior" distances would be affected very little by the doughnut-pattern shot column.
If you consider most shots would likely be within, say, 21 feet MAXIMUM, I doubt very much whether you will even see a doughnut pattern!
Of course, the only way to tell would be to take the loads out that you plan to use for home defense and shoot them at various distances you would plan on shooting within your home to see just how much doughnut-patterning you end up with!
I have a fairly large home and the farthest shot I would most likely take would be within 7 yards, i.e., within 21 feet. I also think that, the larger buckshot pellets would tend to want to go straighter, longer, than say, if you used #8 bird-shot. I am only speculating, as I have never tested my rifled 12 gauge barrel using pellets.