After a few months of using Home Assistant (don’t throw tomatoes at me 
), I find that an interesting feature is missing from Gladys regarding scene management.
In the past, I’ve seen many discussions about this need:
- when motion is detected on a sensor
- turn the light on, wait 2 minutes, turn the light off
But most users encounter the following problem: if several motion detections happen, the scene is launched several times in parallel and the light goes into show mode 
(continuous on/off).
The solution to this was often a virtual device storing the state or conditions (if the light isn’t already on).
But I find HA has an interesting approach to handle this: the scene execution modes.
For the scenario above, the single mode directly solves the problem. If the scene is currently running, a warning is logged and it won’t be started a second time.
We could leave the parallel mode for existing scenes. And the other modes might be too complex today 
What do you think? If the demand is strong, I can draft a specification.
