First year choice test

Hi, I have a query regarding my tax filing in USA.

  1. I was in USA from 2012 till 2017 on L1 visa and I filed my taxes for all these years normally.
  2. I moved back to India in April 2017
  3. I came back to USA in October 2020.
  4. if I file my tax returns for year 2020, I have to file as a non resident in a simple scenario. But if I take the first year choice test, I can file my returns for 2020 as a resident after passing substantial presence test in June 2021.

My question is - Am I eligible for first year choice test in 2020 even though I was in USA from 2012 till 2017 and have filed my tax returns with IRS? Please note that I haven’t used the first year choice test earlier anytime.

Is it a good option to go with this test and save $1500 by filing as resident in June 2021 (extension applies)? Or file as a non resident and pay additional $800 as taxes?