not satisfied with layer 3, so i am going back over it with a new technique: on a user defined layer, i'm drawing lines ONLY where i see a visible plane cut in that layer. then i'm adding "S" on top of every via that has spoked connections to the copper on that layer.
ahh that makes more sense. there are a few higher current connections, but more importantly, there are cuts in the ground plane! this creates a star ground at the large highlighted pad near the middle. this is the negative battery terminal (but after the current sense resistor)