Workers who hold H-1B visas can only work in the activities described in their petition for the H-1B. If the contractor you're planning on hiring is going to do the same work for which he or she petitioned, all you have to do is fill out a Form I-129. However, if the H-1B visa has been "sponsored" by a particular company, this may not be transferable. Speak to an immigration attorney to get the guidance you need.
Creating a MAP will take no more than an hour of your time every month and will keep the lines of communication open, ensuring relationships with investors remain strong, and ultimately helping early-stage startups succeed.