Neuro Vault: Played straight. Only the old-time classical version, though, where you hide it in people’s memories using good old-fashioned memory palace techniques, or closely related gnostic overlays emulating them. The trouble with imprinting stuff on bits of the brain that aren’t the usual memory regions is that it tends to show up as a pretty clear anomaly on a mind-scan, if anyone cares to look, unless your courier is already going to be drawing attention to themselves by virtue of exotic and unusual mental architecture.
Powers As Programs: With the availability of mnemonesis to download knowledge and skillsets into your brain, gnostic overlays to do the same thing for professional personalities, and the ability to download recipes for your portable nanolathe or desktop nanoforge to build you the tools to use them…
…yeah, this is pretty much the way it works. Although those powers which require genetic changes, large tools, exotic materials, or significant ‘shell modification are somewhat more difficult to achieve.
But see also Skilled, but Naïve, when we get there.
Neural Imprinting: Ubiquitous, although it’s called “gnostic overlay” and “mnemonesis”. And while it is the standard educational technique (starting prenatally, with the axiom feed), it’s only the first step. After all, being able to download huge chunks of skillset into a chap’s brain is easy; successful integration and synthesis to make said skills your own is hard, and then practice, practice, practice!
Of course, in terms of pure fact-memory, being able to recall just about anything known by remembering it certainly helps. Assuming you have the intelligence and intellectual skills to do anything with the data, which is the hard part there.