How to determine working envelope for YuMi?

Hi all. I am working on a project using YuMi and because of my desired working space is too close to the limits of YuMi reach, I need to find the best work object (object frame) orientation to fit my working area in which is a 800*600*200 box on Right Arm.
Currently I am looping into space using CalcJointT to loop in different object frames having defined 8 corners of the box as robtarget trying to find valid configurations using CalcJointT.
Any thought would be highly appreciated!