High Level Aeros
I seem to remember with the later marks of JPs being taught high level loops.We used to go above 30k in the Mk5, demo a high speed (!!) run then go into a Max Rate Turn to demo compressability. Following that, a descent IIRC to @25k to show a loop.
As for the spacing of the Meatbox engines, I always understood it was in case the jet turned out to be a white elephant and it left room for piston/prop replacement