First of all, this is the best kanban/taskboard plugin I've found for Redmine ! thanks for the effort in building it and publishing it.
I noticed that the issues here do not respect Redmine workflow (transition limitation between issue states), associated with that, I see that the issue is not commented with the "user" changed the state from "foo" to "bar", I think both are consequence of not using Redmine own logic to change issue state, but I was not able to find the code were the transition happens either on this plugin, either in redmine.