Yes - that helps a lot.

If only 5 to 8 channels are actually 20 A, and the rest are only 5 A fused, the design becomes much more realistic than a full 16 x 20 A worst-case board.

Your board is no longer a pure 320 A worst-case distribution problem. Instead, it is a mixed-current power distribution board, which is much easier to package safely if you separate:

That matches the guidance that high-current routing should start from estimating net currents and then assigning routing width/geometry from those current estimates, instead of treating everything like ordinary low-current nets . The attachment workflow also emphasizes analyzing technical documents and tying the result back to the actual design constraints rather than giving a generic answer .

With:

I’d say:

Use the PCB for:

Use the heavy wiring for:

Even with 5 oz to 8 oz copper, I would still avoid long shared copper runs carrying the sum of many outputs. Heavy copper helps, but good architecture matters more than just copper thickness. The project-analysis guidance is clear that current budgeting and routing strategy should be determined up front from the power architecture .

This is now feasible, provided you:

If you want, I can help you next with a practical layout architecture for:

and show the safest way to arrange the power entry, fuse row, and output rows.