I can't seem to understand the necessity to reset the transform matrix of the ShapeRenderer, since it's used only inside this EditorStage, 
I think we could avoid this process `Matrix4 m = sr.getTransformMatrix().cpy();` and `sr.setTransformMatrix(m);`. Plus Matrix4#cpy() method creates a new Matrix4 (60 times every second) which would create a lot of GC in Android.

If it's completly necessary, and this process cannot be avoided I would recommend creating just once per Group a Matrix4 called "oldMatrix" and using `oldMatrix.set(sr.getTransformMatrix());` avoiding so the GC problems.
This could be easily done if we send a pr to libGDX asking them to create this method in [Group.java](https://github.com/libgdx/libgdx/blob/master/gdx/src/com/badlogic/gdx/scenes/scene2d/Group.java):
```Java
public Matrix4 getOldBatchTransform(){
    return this.oldBatchTransform;
}
```