(o) Prior to the time the principal broker or the broker-in-charge is absent from the principal place of business for more than thirty calendar days, and no other broker-in-charge is registered for the principal place of business, the principal broker shall submit to the commission a signed, written notification of the absence designating a temporary principal broker or temporary broker-in-charge, who shall acknowledge the temporary designation by signing the notification. In case of prolonged illness or death where the principal broker or broker-in-charge is unable to act, another broker shall be designated as the temporary principal broker or broker-in-charge within thirty days of the illness or death with appropriate notification and statement of a licensed medical doctor certifying to the commission the inability of the broker to practice. A temporary principal broker or broker-in-charge arrangement shall not exceed a period of six months unless, prior to expiration of the initial six-month period, the principal broker requests and obtains, upon a showing of good cause for such extension, approval of the commission to extend the temporary arrangement for up to an additional six months.