Ability to reassign a task to another Parent

Hi Aymeric

It Would be great to be able to move a task/sub-task to belong to another Parent or Big Rock.

At times I create  4 different Big Rocks each with a Long check list, then I later realise these 4 Big Rocks converge in to one Big Rock....would like to be able to drag and drop them in to that common Big rock

Cheers