I would have done the same thing, return the CX and strick with what you 'know' works.
I guess were it not for the error in calculating the vanes & assuming a 100 BH instead of the 125 you are actually using--I said the vanes were 32 grains--but that should have been 24 ( 3 vanes @8G ea---I mistakenly calculated for 4 vanes)..the estimate would have been there.
45/60 shaft 228g, 125g BH, 15g Insert, 10g Nock & 24g vanes = 402g total. Just like you said.
Still with the CX200 and the 125 BH (same set up) it would have weighed about 342 grains, you would have dropped short about 8 grains for recommended spec---5 grains /per pound.