Honestly, in my view, the key was a short, one-page letter, and trying not to sound pitiful (I asked my friends to read it and made sure it wasn't the case); I wrote literally 3 paragraphs, explaining that (1) I am physically present in Canada, (2) my work permit is about to expire, (3) how getting PR before end of summer could help me professionally. Also, I didn't want to sound like I deserve anything better than other applicants, and my file needs to be processed faster. I just said that I was hoping that this information will help to expedite the processing of my application and yet, I understand all the delays due to the pandemic.
Let me know if you have any other questions and I do hope that every one of you will get the COPR!