State tax filing

Hello, I started a conversation with PR advisors and they are saying me the form 480.6C is only for residents of PR and therefore I don't need to fill in a PR income tax. My question is: What's the problem if I don't fill in PR income Tax? Is it just related to the credit Tax amount? Any other inconvenience? Thanks.

Doubt: How's about as an alternative, I enter the amounts from form 480.6C as an income gained abroad?