This is one of the use cases we discussed a longer time already.
While it seems like it makes sense in the first place, this kind of auto-expansion gets more difficult when more pools are involved. Consider the scenario shown below: How do you distinguish dropping the task onto the source pool vs. the one next to it?
Earlier we decided not to implement the feature as it’s quite hard to guess user intend in more advanced scenarios. Your pointers and feedback is appreciated; maybe we’ll give it another try some time.