I need to know if anyone has experience with transferring job once they found a SOFA status position in okinawa.
You mean to another government (SOFA) Job, or to a Japanese company?
SOFA doesn't come into play here. If he wants to become a permanent Resident of Japan, he must follow Japanese immigration laws. SOFA bestows upon him American rights in a foreign Country. he would have to give up SOFA status to become a Permanent Resident of Japan.
You can keep your SOFA if the company has it to offer. This is not rocket science and and it's not a secret. You can ask them, up front, before you apply and they should be able to tell you. If you going to okinawa is dependent on this answer then call the companies in which you're interested.
