ACCOMPANIED BY JOB OFFER- Each application filed under paragraph (1) shall be accompanied by a copy of the job offer describing the wages and other terms and conditions of employment and the bona fide occupational qualifications that must be possessed by a worker to be employed in the job opportunity in question.So...they must have a written job offer,which means they DO have a specific job lined up.Don't specifically see anything on changing jobs, but these two sections seem applicable...
WORK PERMITS- During the period in which an alien is in lawful status under a guest worker program, the alien shall be granted authorization to engage in employment in the United States in the job opportunity approved under the program and be provided an appropriate work permit that includes a photograph of the guest worker.This would indicate that they would have to have prior approval or a legal complaint filed against the employer. This is consistent with other guest worker programs, as they do not allow "job hopping". Couldn't find anything on legal documents other than the employers have to provide vehicle insurance if required for the job.PROCESS FOR COMPLAINANTS TO OBTAIN OTHER EMPLOYMENT- The Secretary of Labor and the Secretary of Homeland Security shall establish a process under which a guest worker who files a complaint regarding an employer who intimidates, threatens, restrains, coerces, blacklists, discharges, or in any other manner discriminates against an employee because the employee has disclosed information indicating an employer violation of the guest worker program to enable the employee to seek other appropriate employment in the United States for a period not to exceed the maximum period of stay authorized by the original permit.