I'm waiting for this 2 years.
And need ability to add the expression. For example need to monitoring variable in multidimensional arrays. Why we must add to watch all Array, when we need only one variable myArray? Or myArray[x][y][z].
Also Flashdevelop can't remember watches and nees to add them to the window every debug session.
Unfortunately in the version 4.0.1 is changed nothing of this.