A booster will make it easier on foot pressure. Nothing else. You do need to wait til you get the rear drums changed to do muvh thinking on this. But as said, shoe brakes need to be pretty close to dragging when set up. Also maybe the proportioning and/or residual valves need adjusted or eliminated.

I assume you have set the MC rod to just 1/16 travel before it starting to push MC piston.
I assume you bench bled the MC before install.
disk/drum is very common.
Never heard of disc/huck but I don't know anything wrong with it.
Be sure pads are really close to rotor also.

Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn