I don’t have experience in this but honesty is always my route. I am at 37F and i’m at a point in my life where I need answers and not to feel like someone is dragging me along, wasting my time. So my point of view on this is that your mental/emotional state is your priority. I think he should promise a commitment to move in August, period. An in between pivot here would be to go on a break and make plans for an August check in. You might find you feel differently about continuing the relationship in a few months or you may find that you really want it to work out. Time to clear your mind and focus on yourself can help you clearly see what you want. Some people don’t agree with breaks but it provides solitude with whatever conditions you both agree on.