Ah, I saw the title and was like "yeah, this is easy to do I wonder what the trouble is..." Then I see you've specified mapshift mode, and that's the answer xD
The thing about that mode is that it's a completely separate control scheme that takes over the basic commands of the game, and is purely capable of exploring the map to look around, not accepting other normal input. It was added solely as a way to enable Linux players and vi-key users to look around without using the Alt key. But if you use any of the other map examination methods, including the Alt method, you retain all normal controls, including waiting, so you can watch drones as they do their thing.
As a modal input scheme by design, mapshift mode can't accept other forms of input. On thinking about this a little more now, considering the occasional importance of what you're trying to do here, perhaps changing mapshift's default behavior would be a proper solution: Basically instead of having mapshift mode automatically recenter when it ends, just leave the view where it is and require manual centering if required. This would technically be consistent with all the other shifting modes.
I could make that change for the next release, and until then you could use Alt-arrow keys if you want to follow drones and retain control for waiting.