Outside advisers to the U.S. Export-Import Bank this week debated whether the bank should formally recommend lowering its domestic content requirements for financing to compete with China, adjustments that opponents charge would face steep resistance in Congress and could jeopardize the bank’s reauthorization. Under Ex-Im lending rules, U.S. small businesses are eligible for export support from the bank if each of their exported products has “more than 50 percent U.S content based on all direct and indirect costs, including but...