I know the Jaspersprite that formed Jasprose was from the Game Over timeline, which has left me confused. Is there another Jaspersprite hanging about, and which other Sprites are 'in play' so to speak?

Yes, there is another Jaspersprite around.  There’s also Nannasprite, Tavrosprite, of course Jasprosesprite^2, and Arquiusprite, but I doubt we’ll see him again.