Does make me laugh when people mention upgrades that are considerably lighter in weight for components.. Great, a lighter engine.. Those lighter engines will require weight being removed from the front end to keep the C of G and MAC within limits.. Or additional ballast at the back..
Tailerons?? On a Jaguar.. Please don't dirty the aeroplane with that Tornado terminology. At above 400 Knts, they are tail planes with only pitch control function. Only at lower speed or selected by the pilot can differential movement be applied to the assemblies to produce a roll moment (because the roll spoilers on the Jag are useless at medium angles of attack or low speed). That sub system for roll was called Differential Tail Plane.. Tonka's work at pitch / roll all the time and any speed (spoilers used to enhance low speed manoeuvrability) so are proper Tailerons.