A logical hypothesis is, by definition, developed a priori.
If a man enters a room known to have only one egress, and you are watching that egress, and have not witnessed the man exit the room, then you could easily develop a hypothesis that he has not left that room. In the same analogy, if the room has a secondary egress, but it is far more difficult to use (e.g., a fire escape through the ceiling), it would still be reasonable to develop the same hypothesis.
Theorizing about things based on what seems likely and what seems unlikely, given whatever knowledge you do have, is perfectly reasonable within this kind of framework.
Without proof or evidence to support your idea, you're just brainstorming a scifi novel.
Before securing evidence, you must theorize a hypothesis.
Its figured out how they built them.
A logical hypothesis is, by definition, developed a priori.
If a man enters a room known to have only one egress, and you are watching that egress, and have not witnessed the man exit the room, then you could easily develop a hypothesis that he has not left that room. In the same analogy, if the room has a secondary egress, but it is far more difficult to use (e.g., a fire escape through the ceiling), it would still be reasonable to develop the same hypothesis.
Theorizing about things based on what seems likely and what seems unlikely, given whatever knowledge you do have, is perfectly reasonable within this kind of framework.