VK_NV_DEDICATED_ALLOCATION fails with memory types that aren't device local

I don’t see anything in the extension description that mentions this is supposed to be the case, was it an omission or is this really a problem? Also equally interesting is that if I remove the extension after failure and try again future allocations fail which seems like a bug.

I’m running latest Win10 x64 on a Macbook Pro with a Geforce GT 750m and driver version 376.33.