When MKOs are conformed by all kind of tacit and explicit knowledge constructs in one’s PLE, there is no way of (a) “using them up” and (b) not being able to move in parallel with more than one more knowledgeable other.
corresponding ZPDs, it is also true that, from a static point of view, they need to be built to scaffold your way through a specific ZPD. And it is in this scaffolding that help is required.