Especially with the introduction of the new switch puzzles, it would be very helpful to have a hotkey that would switch between the bound and unbound aptamer states. In general, the UI has a comprehensive set of hotkeys (although, as has been already reported, they frustratingly often stop working when advanced energy views are turned on). But the lack of a key to switch between states makes the switch puzzles, and indeed the switch labs, frustrating to work on.
I definitely agree with Drax. I miss that option here, that we have in puzzles where we can use spacebar to toggle between natural and target mode.