My gut feel without the support of any evidence is that the symptoms of amine sensitivity all appear to be from an unnatural dilation in the blood vessels. Those symptoms don’t seem to be shared with a lot of the symptoms observed to appear to resolve in people on a ketogenic diet. I haven’t heard of anyone claiming that a ketogenic diet altered amine or salicylate sensitivity but it could just be that not enough people with those sensitivities have tried to the diet to have sufficient anecdotal data.
Ketones do have an effect on the health of the vessel walls, but it has only been shown (by Jeff Volek) in experiments to improve the dilation in the normal pulse of vessels constricting and dilating. So I’d guess that this may not be helpful - but I suspect you could formulate a specific keto + amine senstivity diet and see better endothelial function at both constriction and dilation phases.