I am in the process of designing a drone for military field use. I have a general concept for it, but the whole thing needs refinement to get it to a prototype worth state. The current concept is a high endurance, medium altitude, ultra long range, easily portable, VTOL, UAV for ISR and light payload delivery. I have looked through hundreds of existing UAVs and this seems to be one of the few untapped niches of design, but I am wondering how much practical application it has. My reason for this post is to ask for feedback on modifications I should make to design and mission roles to maximize its applicability. I am more than happy to provide any additional info needed.