Question regarding Labor Certification and Green Card Application

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I am working for a company as a Quality Systems Specialist on H1-B visa. My employer is filing for my green card under EB-2 category as I have an advanced degree. They are applying for the the PERM labor certification for the job of Manager, Quality Systems. Now my intention is to work in other departments (logistics or sales) on my next assignment. But they cannot apply for PERM for a job in Logistics or Sales as right now there are too many people available in that field and plus I do not have experience in those fields (hence it would be difficult to get labor certification). I was told that I can accept a job in another department but I would have to become Manager, Quality Systems at the time when I am supposed to receive the green card. The USCIS would have to be informed of any interim changes in my job position. Is there a risk involved in doing this? Can the the green card application be denied midway when I change jobs since the other departments are not relevant to Quality (the original application)? Would the green card process have to be restarted at a later stage? Please advice. Thanks in advance.