So a thought occurred to me but I don't have an item to test it with, so I'll ask here.

If an enhansive item runs out of charges, do we still need the potion to permanently ensorcell it?

Starchitin

A severed gnomish hand crawls in on its fingertips and makes a rude gesture before quickly decaying and rotting into dust. A gust of wind quickly scatters the dust.

This should (conceptually) be no different from a Fusion item with no orbs.
(And the answer to that question is, "Yes, you do.")