Hmm... Perhaps I've misunderstood you. But my point is to avoid having to manually enter a value for the Timer thing altogether.
Referring to the scenario if the Timer thing could accept a variable input from the thing before it, we could do this:
Location(1): Trigger start of flow when leaving an area.
Traffic: to obtain the commute time in minutes.
Math: perform timer input calculation
Timer: Pause xx minute before flow to next thing.
Location(2): confirm entering home area before flowing to next thing.
FlowConnector: sequence of actions eg turn on lights, heater, Alexa/Google home, turn off security etc...
So it doesn't matter how long the commute is going to take from work to home, Traffic is triggered to get the estimated commute time right after leaving work automatically, passing the variable to Math and then Timer thing to carry out the action just before arriving home, regardless if the traffic is heavy on Friday evening or light late in the night. Instead of having a fixed value pre-defined in Timer thing in the flow.