Should I file TN extension amidst pending I-485, and are there risks?

Good question. I am of the opinion that this can be done, but there is of course the issue that you are applying for an extension of a visa status under which you are supposed to still be maintaining nonimmigrant intent. There is a good possibility that USCIS will flag you and the company on the issue, and the company would have to give a response. But in the meantime, you would have extended work authorization by having timely filed a TN extension with USCIS. Hopefully, your EAD is approved prior to your expiration so that you do not have to make a choice of either doing the extension or stopping work for a period of time. I do not believe that this would adversely affect the I-485 as long as the adjudicator is reasonable. Good luck. Due to the limitations of the Lawyers.com Forums, Alan Lee & Arthur Lee, Esqs.’ (the "Firm") participation in responding to questions posted herein does not constitute legal advice, nor legal representation of the person or entity posting a question. No Attorney/Client relationship is or shall be construed to be created hereby. The information provided herein by the Firm is general, and requires that the poster obtain specific legal advice from an attorney. The poster shall not rely upon the information provided herein as legal advice nor as the basis for making any decisions of legal consequence.