I figure it'd be nice to extend this to all armour
That is what I understood - you could upgrade anything (boots, armor, hats, rings, pendants) and the armour would increase. Or you could upgrade any weapon and it would too - presumably updating magical/physical to be in line with your level.
So you could (with a *lot* of runes obviously) upgrade the entire braccus set, the amulet from the deepdweller and the sword you get for killing Slane (shame on me) or Dallis' Hammer.
