The easter egg unique component Avro Arrow which replaces the Jet Fighter felt kind of mediocre, but of course now that I check I realize it's not meant to be a proper UU.
... it could be made to be an actual UU by being unlocked earlier than the Jet Fighter, at Satellites tech instead of Lasers. Even then a often cited potential factor in the Arrow's downfall was the launch of Sputnik indicating a coming Soviet priority shift from nuclear bombers to nuclear missiles, which could use a mention in the civilopedia entry if it actually gets one.
Problem with very late-game UUs is that one might never get around to using them. But by being unlocked at Satellites it would come with an otherwise non-mil tech, so if Canada's going for a more peaceful defensive playstyle, they don't have to go out of their way to pick up Lasers (which is almost entirely offensive mil focused) to use the Arrow.
And of course it could also get free Interceptor (and maybe Range) promotions in exchange for slightly reduced strength across the board.
Food for thought if there is ever Vox Populi 5UC or 6UC update I guess