Hello!
Still, you could have like a dummy mission map, that would display your current map with one playable actor at a given position (entrance or CC). The Battlescape would be called from within the base management screen (window 'Building').
If there is one thing that is not shown in the UFOpaedia, it's the various levels of any multi-level building, as well as its footprint at the surface. Before the first base attack, you can't know that this building will hinder line of sight, or this one is best to build if you want a clear view to decimate the invaders from afar. Indeed, on my first base defence, I spent several dozen of minutes to investigate my base (before terminating the last Aliens). I would have prefered to spend this time while not in a combat mission. What buildings have doors to the surface? What have flat tops? Why build large hangars along the map's borders. How a Workshop or a basic Radar Tower may lure some Aliens on the surface and diminish the pressure on the Entrance... (etc.)(v25)
I even once designed a base with small hangars and quarters built so as to cut the surface in two (both buildings block the passage on the surface) to force the Alien spawned and trapped there either to use the large hangar to enter the base, or to await destruction by indirect fire.
Either use a 3D engine in the UFOpaedia to display and rotate true models, or rather, as I said, allow to enter a dummy mission from within anywhere (Base management window, or even Geoscape, when you select a base).
