Abstract: I will discuss a conjectural definition of refined curve counting invariants of Calabi--Yau threefolds with a C*-action in terms of stable maps on Calabi--Yau fivefolds. The corresponding disconnected generating function should conjecturally equate the Nekrasov--Okounkov K-theoretic membrane index under a refined version of the GW/PT correspondence. I'll present several acid tests validating the conjecture, both in the A and the B-model. This is based on joint work with Yannik Schuler (ETH Zurich), arXiv:2410.00118.