I’m thinking that a rapid iteration cycle, combined with requiring early feedback and requesting clarification often, will do the trick fine and allow us to launch an MVP much earlier than if we were to wait until a proper, detailed functional/technical spec was made. This of course would not be the case (most likely) if our project was properly funded and had a full-time professional requirement analysis team working along a professional full-time documentation team under a project manager’s supervision. But given our constraints, that’s just not happening so we go with the next best strategy.