Re case mouth chamfering and deburring, why not flare the case mouth as is the practice when seating cast bullets. If the bullet seating die is custom made or at least dimensions are held tight in manufacture of the die then the case mouth flare is removed as the bullet is seated and then crimped.

I flare case mouths for my 404 Jeffery and cast bullets using a 45ACP case flaring die, only the 404 case neck goes up into the die stopping at the case shoulder. I just turned the flaring spigot down to a good fit into a resized 404 case mouth and the flare shoulder does the rest. My bullet seating die irons out down the flare and then a good crimp is applied, if a crimp is wanted.
Gas checked bullets will start into the neck flare by hand so case and bullet can be put into the press and up into the seating die with nil bullet shaving.