Final IK needed to solve my IK issue?

Hello all, I have a question about IK issues. I’ve got an avatar that has a sort of digitigrade set up for the legs with three leg segments. However, I’d like to maintain independent control of all three leg segments as I intend on using custom locomotion animations. However, as far as I can tell, any attempt to add a third leg segment causes the default humanoid IK to have problems. I presume that final IK would be a solution, however I’m not sure how exactly to implement final IK. Do I have to create a generic rig and then use final IK for all IK considerations? Can I use the humanoid rig but just disable leg IK and then add final IK to that? Does anyone know of a way to get around adding additional segments to a limb without causing problems with IK without final IK? Figured I’d ask before spending 90$ on final IK. Thanks.