Those links will be extremely helpful, thank you so much! Do you know if they cover how to build an IK system for general rigs?
Also, I was looking around the asset store and came across the Skele Animation tool. Do you have any experience with that? It offers constraints and IK along with a lot of other things. But it seems like it might be pretty specific to humanoid shapes. If not no worries, I was just curious 🙂