Thinking of switching from M1 single plane to LD340 but LD340 would need to be milled to fit. Is it worth it?

I really hope you meant 2.02 intake valves in your heads... :lol:
Personally, I would have the heads' manifold surfaces cut instead of cutting the manifold. That way you can run any unmodified manifold you want without having to repeatedly have manifolds remachined.
oops, yes, 2.02. My bad! Corrected. I'd rather just keep the current M1 setup that to pull and shave the heads at this point.