Tree Texture Altas Size

Is there any option to change the size of tree texture atlas generated with Tree Creator?

The automated atlas creator always makes texture 1024x1024, independent of the size of individual textures, and it drives me crazy, coz i loose alot of quality from this.

Or is there any way to change textures in the Optimized Bark/Leaf materials, so i can easily create texture atlases myself?

Same problem here..