A corner aluminium insert supports the part of the motor and produces sufficient ac and adverts tightness. The best insert can be used to enhance flex as required dependent on each track. The inserts are associated with machined flanged threaded alu peanuts from top, so the carbon wont harm.
The framework with both inserts is all about 60 grms lighter set alongside the exact same in aluminium.
Serpent metal weights could possibly be used to place the excess weight in preferred places.