What do you want to achieve?
A method on how you make a walking animation ‘blendable’ with IK footplanting.
What is the issue?
I don’t know whether to use CFrames or some other method to make the footplanting compatible with the walking animation.
Unless you need complete photorealism too small for the human eye, you can just follow Griffpatch and disable footplanting while walking. BTW Griffpatch is a Scratch pro, and Scratch is very stupid sometimes. Otherwise check if the feet are near the ground and footplant them if they are.
If I change the CFrame of a limb, will the walking animation keep working but with the new CFrame of the limb?
If your standing IK works, then your walking IK should work. As far as I remember changing Positions/CFrames via code doesn’t break joints.