I think it fits for skills to be unlearned by default but you could have a true or false setting in the plugins parameters. What happens to switches and states gained through common events when a skill tree is reset? They should probably reset as well. My idea is for a skill tree is for stat ups for each parameter using a variable to increase the cost and having the node unactivate after each use so the same node can be used again but at a higher cost. I think this would be absolutely great. The issue I see is I don't think we can use a variable as the cost currently. I don't know if that would be difficult to implement or not. I would assume it would be as hard to code as adding switches. All I know is you have done a great job and I am looking forward to a great plugin update.