Yeah, I guess if "approachable and friendly superhumans who like, if a bit patronizingly, regular humans" is your definition of Elf.
For me, and this is probably a GW thing, Elves always seem to be light, fragile specialists. The Infranites are the exact opposite! Heavily armed and armoured, outfitted to take a reasonable sort of a swing at virtually any mission.
Personally I'd say the Infranites are somewhat close to the Numenorean/ High Man trope, while the psychic-dominated, ancient and archaic Black Empire with their ritualised and rigid battle-orders are somewhat Elfish.
To me the Infranites might be a different species, but their overall feel is "bigger, badder Humans". They approach trade and war in a very human fashion, have a smaller population and marginally better tech. They use guns, not exotic super-weapons, which is actually a bit more primitive than the UNE laser/plasma paradigm, but they've perfected firearms to a remarkable degree - like the idea of ancient heroic smiths forging Damascus steel blades; human, mundane, ancient, but also superior.