I do have also another feature request I quickly checked the Android version of Situations and it doesn't seem to have this, either.
Let's say one wants to have wifi enabled and mobile data disabled in some locations, and otherwise have wifi disabled and mobile data enabled. One way to do this is to have defined areas/locations (e.g. by cell IDs, just like in Situations currently) and on top of that events like "left area" and "entered area". Then, when entering a specific area, mobile data would be dropped and wifi enabled, and the opposite would happen upon leaving. I'm not quite sure how much an unused wifi draws power, but IMO at least maintaining mobile data when it is not needed is a power hog that can and should be eliminated.

This would enable, in addition to the above example, having ringer volume turned up when leaving home (to be able to notice it better while in noisier surroundings) and other such things. Some cases can be managed by having a generic situation (with a high ringer volume) which then is overridden by more specific ones, but that approach makes it necessary to have extra situation(s) just for the baseline/default condition(s).

Additionally, to handle the area borders nicely, as the phone might alternate between cells in and outside of the specified area, there would need to be a sort of a dampening to avoid rapid switching between situations... something like a configurable timer attached to the enter/leave area event so that when initially entering the area, the timer starts, and if and only if the condition still holds after the timer runs out, the situation is triggered (and similarly for leaving an area).

Edit: good to hear the timed manual situation is on TODO list. I'm a bit new to the Sailfish way of doing UI and can't come up with any good suggestions right now...