are PTE plates consumables? ive been printing petg (im the guy that had adhesion probs in this thread) and when its successful i notice print shadows/streaks on the plate that don't go away with IPA. so i hella scrub the plate with dish soap and a dish sponge (rough side). works fine so far, removes everything. but im wondering if im not supposed to do it every time i print petg and see marks to prevent wearing the plate down