What if the boss deliberately delays the re-appraisal of work-related injuries?

According to your description, it is not excluded that the boss, that is, the employer, is liable for compensation for maliciously delaying the time. But in the legal procedure, the practice of the employer is also in line with the law. The law protects the rights of workers and employers. Therefore, employers also try their best to protect their rights within the scope of law. If you want to solve the problem as soon as possible, you can try to communicate with the employer to solve it. It is suggested to consult a lawyer before communicating with the other party to effectively safeguard their legitimate rights and interests.