How can I best prepare a BDE SIG CO to be ready for an XCTC rotation as a CO XO? What sort of developmental planning and products will help?

Do you have Signal experience? I would look at training for collective tasks and individual tasks. Technical skills and tactical skills. https://work.chron.com/army-executive-officer-description-19835.html

Perhaps u can contact http://www.xctc.org/ and see what their training criteria are.