Pushing an updated build this weekend, which has a proper support for multiple actions. Previously you would define aciton frames using custom armory ui which was quite clunky and limited. Build 12 started to work on this but exports just active action…
In the next update you can Stash multiple actions on armature like one would expect, and then simply use Play Action logic node or object.animation.playAction("myAction") from script. Hopefully I can get it out by tomorrow evening! 
