Seeking clarity about root motion

Hello good people, i am having some trouble wrapping my head around using root motion with a custom character!

I am working on a custom character with a custom rig, both created in 3DS Max. Now i have seen so many methods for applying root motion to, lets say a walkcycle, but most seem to rely on; CAT Biped workflow, plugins/scripts or mixamo characters, so im not sure what direction to take.

As far as i gather i need a bone centered in every way to the world at the base of my character, but on top of my bone-hirarchy? (This seems to trouble my rig as it has a splineroot in that place currently) So if i walk a straight line, can i just copy the animation axis i follow and copy-pasta this to the new root? And is there a way to make this bone “un-intrusive” to my current bones?

Or maybe i need to use another workflow all together?

Any advice or pointers would be greatly appreciated!