I may not have cottoned onto this properly, but why cant people over the pond adjust to 12kg?
I may seem narrow minded, but i really can see the spinners and the billets taking over. Atleast at 12kg you need to comprimise between weapons/power and armour.

With an extra 1.6kg i could up my armour to 4mm hardox all over, and still have astro drive and heavier grippier wheels. I would have no fun doing that though! likewise i would have no fun building a mega spinner such as the sort JB mentioned could be possible to produce!! Either no one will fight it-or a billet will just bounce off.
If some of the spinners use 1.6kg to increase the power on their disc then everyone else could use it to upgrade their armour.

Thats my views