Business travel agencies have never quite shaken questions about their loyalty. Attempting to address whether they're working on behalf of buyers or suppliers, "open" or "closed" contracts can determine whether clients receive pass-through of supplier commissions. Startup Gallop.ai aims to make money only through a subscription model. It offers a business travel assistant that can make bookings through its own platform or really anywhere the traveler wants. Execs said Gallop was free to do that . . .