BP_ThirdPersonCharacter Collision is restricted to capsule component. How to break it?

As you can see my character shape doesn’t match the capsule shape. I don’t mind the capsule as I can make is fit within my character, but I also want to add blocks of simple collision boxes to create a more accurate collision shape for my character. Adding other collision boxes seems to do nothing - it only uses the capsule collision as reference.

Is there a way to fix it? Or a good tutorial to create your own character controller from scratch with your own collision shapes?