They don't just specify 12 smaller cables for nothing if 2 larger ones will do. There are concerns here with mechanical compatibility (12 wires have smaller allowable bend radius than 2 larger ones with the same ampacity).
One option is to use two very wide, thin insulated copper sheets as cable. Still has a good bend radius in one dimension, but is able to sink a lot of power.
One option is to use two very wide, thin insulated copper sheets as cable. Still has a good bend radius in one dimension, but is able to sink a lot of power.