Seeking for hotkeys, I am occasionally triggered "Explore" mode on. And it confused me good fifteen minutes. Problem is that "exploring" unit have nothing unusual in appearance - I can select it manually, I can move it as I want - but I cannot select it with "U" hotkey anymore. WTF?! Issue became clear for me only after I got item, and it immediately sets path for my hero somewhere in the unknown. ?? Ah! That's it!!

So question:  can you make exploring unit more distinctive? Outline it in the interface maybe? Put special symbol at it? Or maybe simply permanently lit "explore" button at least?