By seated tight do you mean a tight wad of whatever filler you are using? Do you mean actual case tightness, as with a custom sizer? Are you talking about the crimp?
In regards to the first, I have never used toilet paper (I have a wad of dacron that I've been using on different cases for about 40 years) but I don't make the wad any denser than needed to hold the powder at the bottom of the case. I have experimented with tight wads vs. just enough, and have found no real difference. Of course, this is only my experience.