First of all the Soliton1 won't control a sepex motor.... So the fact you couldn't parallel the controllers and expect it to work doesn't matter.Kostov says that regen is native to this line of motors and just a controller is needed to get the regen.
the soliton1 right now doesnt have regen. Kelly makes a 400amp controller that does regen.
can a system be set up that the soliton controls the motor for acceleration and then when the bake is pressed it switchs to the kelly to send energy back into the traction pack?