Would you consider 177Lu-PSMA-617 for a patient with mCRPC that has neuroendocrine features on biopsy but PSMA-positive disease on PET?  

That depends somewhat on the extent of PSMA positive disease. mCRPC is a heterogeneous disease - if the majority of the disease is clearly PSMA positive, then I think it would be reasonable to use PSMA-directed therapy regardless of what the biopsy is demonstrating.