I would NOT use TP for a filler, if you must use a filler. With filler you run the risk of damaging your barrel on the next shot.
for 30gr of IMR3031, no filler needed.
I must strongly disagree with you on usint TP as a fillet. One a 1/4 square of TP is way too small to do anything and upon firing the round, if the wind is in your face, you'll get a bit of confetti hitting you square on.
Personally, I normally use a one grain tuft of dacron to tamp lightly against the powder. I used kapok way before then and never a problem with either. I started shooting cast and reloading in 1954 for a handgun I owned and two years later started centerfire rifles loading for a 30-30. Never had a problem with TP, kapok or dacron. WSere I di have a minor problem was in using a cereal filler, in this case Cream of Wheat. (COW) I was loading 17.0 gr. of SR4759 under a Lyman #457122 bullet, a 330 gr. hollowpoint and used the filler to hold the rather small charge against the back of the shell. No apparent pressure problems, the load was accurate and velocity was about 1750 FPS. One round was a dud, apparently a bad ot contaminated primer. I pulled the bullet and that COW was packed so tight I had to use a screwdriver to dig it out of the case. I've seen one article for sure in print where the author recommended COW as a filler in the 30-06. I would think that if it compacted as hard at it did in the 45-70 that wierd pressure problems could very easily arise.
But even a tamped down full square of TP would not be a problem. I'd be very surprised if a full square of TP even came close to weighing more than a full grain. Granted, some brands are more flimsy than others but even the stoutest most likely wouldn't go past 1.5 grains. Most of tht TP would be consumed in the flame of the blast anyway and not all that much would be blown out the muzzle unless the load was quite light. I have a gallery load for the 30-06 that shoots a 115 gr to 120 gr. cast bullet over 5.0 gr. of Unique. A quarter square of TP is used to hold the powder next to the primer. When I pull the rigger, very fine pieces of shredded TP exit the muzzle and if the wind is in my face, confetti happens. No big deal.
Paul B.