I love what you've done with the game with this overhaul. As an old-timer who spent countless hours with the original X-Com, yours feels like a definitive edition / remaster of the game. With just enough old stuff to still be recognizable as the original X-COM, but new enough so that even for a seasoned player it's interesting and unpredictable again. Bravo.
I also love what you've done with the geoscape (craft and UFO) icons. I've also just had a
genius idea on a (possibly?) fun way to change these. Not even sure if it actually fits your mod, but I have to share it somewhere.
How about making regular (non-hyperwave) radars so that they don't directly show UFO icons, but rather just a "heat map" of probabilities where the UFO is? The heat map's size and intensity would be dependent on the UFO's speed, size and time it has been visible by the radar. Essentially making it so that the radar can "see" that there is some activity (and occasionally you could just fake it without an actual UFO being present), but you wouldn't know the exact location and you would have to send in a craft for visual confirmation. This is where the "radar upgrades" for crafts which I have personally found not to be very useful would come in real handy. With the time aspect you could also just wait (perhaps risking losing the UFO), but eventually the location should get small enough so that typically you just detect the UFO without extra effort. But you'd have less time to react.
Basically you'd get a map like this on your geoscape, the perhaps generated pseudo-randomly:
Now I get that this would be a lot of work (provided it'd be at all possible) and it's probably a lot of work for a minor and possibly contentious feature... But I just came up with the idea seeing that radar shot, loved it and had to share. So, uh, yeah.
Thanks again for the mod!
Edit: oh and congrats to me for 100 messages (and logging in after 8 years) ¯\_(ツ)_/¯