Honestly I think the Hands would get hit on the list before any Artifact card. They carry most of the weight in HATE, have been out longer, pretty much emptied out their bottle of money-making in DoL, and are an omnipresent metagame-shifter that practically made FF variants extinct. These guys are mained in almost every meta deck in some form.
Comparatively, Ignition is relatively mediocre when there are so many Artifacts floating around, and the thin Artifact engine is more of a disruptive arm of the body in HATE. They are also still making money off PRIO, so why would they knock off anything from that set?
I agree that Tenki could use a limit to two though. Hands to one ideally as well.
We'll have to wait and see on Shaddolls, but you'll more than likely be right. They're Evilswarm MK-2, although Satellarknights as a whole (lol Constellar MK-2) are less of an interesting archetype ironically.