(a) The commissioner by rule shall establish whether the certification requirements established under this chapter for sale by an agent of a designated product or product line apply:
(1) only to an agent who, as of the effective date of the certification requirement, does not hold the underlying agent license required to sell that product or product line; or
(2) to each licensed agent who engages in the sale of that product or product line.
(b) If the commissioner adopts rules requiring each agent described by Subsection (a)(2) to be certified under this chapter, the rules must specify the date by which the agent must comply with the certification requirements.