Except as described in section 387.433, transportation network companies shall not be considered employers of transportation network company drivers for purposes of chapters 285, 287, 288, and 290, except when agreed to by written contract. If the parties agree to the applicability of one or more of such chapters in a written contract, the transportation network company shall notify the appropriate agency of the election to cover the driver. If the parties subsequently change this election, the transportation network company shall notify the appropriate agency of the change.