So after reading TLM, I got to thinking about the fact that each god metal can be alloyed with the 16 known existing allomantic metals to make new ones that bestow new abilities. Presumably a mistborn could burn these and achieve effects. What about mistings, though.

1) Are there mistings for all 16(?) alloys of lerasium and all 16(?) alloys of atium (assuming that an alloy can only be two - are there WoB on whether you can triple mix?).

2) What about mistings for trellium alloys? If those exist, when did they begin to exist? After trellium started appearing on Scadrial or where there always mistings for those?

3) What if Cultivation comes to Scadrial and starts producing her god metal? Are mistings born for those alloys, or have there always been mistings for all alloys of all god metals? Is that why not everyone with Allomantic DNA shows aptitude for known metals?

Random late-night thoughts. Maybe Brandon has answered this and I couldn't find the WoB.