Another idea for buss bars is the buss plate ?
Searching out other controllers on the internet I found a controller called the Soliton1 made by EVnetics.
They designed their high-end Soliton1 Motor Controller to compete with the Zilla Controller.
Their high performance controller the has a lot of innovative features including; A multilayer buss bar design using contoured 0.090” copper buss plates with Mylar separators (see attached picture). The controller is designed for IGBT modules, but I think that getting creative you could mount a re-designed Revolt power PCB with discrete MOSFETs & Diodes to a copper multilayer buss bar design using copper standoffs ???.
Another interesting feature is a single (1) film capacitor CDE 947C. No– electrolytic capacitors are used in the controller