A shortfall in customer funds revealed at Peregrine Financial Group last month renewed calls for an insurance program for futures customers, but the plan still faces many hurdles, including getting legislation approved by Congress. “I’ve put this proposal out there because we need to move this discussion forward and get a new law on the books to better protect customers,” Mr. Chilton said in an email. The fund, as Mr. Chilton outlines it, would be modeled on a similar insurance plan for securities customers and would be created by collecting fees from futures brokers “which would under no circumstance exceed…