回複：DIY on EB1/NIW, question on self-petition letter?

Nothing wrong if you use first person when writing a self-petition letter. Have you read those personal statements written by candidates for public positions such as the ACS president? Search the internet and I am sure you will find quite some examples.

P.S. When your boss writes a recommandation letter for you, he uses "I" to address himself, right? And he uses a lot nice words to describe your contribution/merit throughout the letter, right?