Rite i think and only what i think that should be on the zx6 is,
All alloy to be done in kyosho red.
Kyosho gold turn buckles.
I think back to belts like the 1990s zx alot smooother (my thoughts only).
Small bore shocks.
Carbon fibre shock towers 4mm and 5mm as option.
Quick release shock bolts.
Slipper nut you can get too.
Center motor design more like tamiya 511.
Belt covers.
Carbon fibre chassis.
Lipo trays.
Nice only my thought for what its worth.