I don't know much about this 60 minute wait honestly and again, Exodus is using ShapeShift.io API so this has nothing to do with them I believe. It should logically work like any other exchange, you make the order based on the current rates and the price can't simply double just like that... feel free to explain your question more because I'm not sure If I got it right.
When you click exchange your get the current order price but your asked to wait a while, it is not instant, so what happens if the value increases during your wait? Would you get that increase?
When you give the order the price is set. They (shapeshift.io) are reserving the coins for you at that rate. Exodus is always sending with high priority so normally within the timeframe of shapeshift.
When you exchange thru shapeshift outside Exodus, there is a chance your payment takes too much time; then the order is cancelled, but within Exodus it shouldn't be a problem.