Given that the site is generally pretty lax with whitespace at the end of the line, it doesn't feel unreasonable to allow solutions that use carriage returns instead of newlines as line breaks. The site would probably still need to be able to distinguish between the two because of the quine hole, but other than that there doesn't seem to be much of an issue with this. It's worth considering whether a newline followed by a carriage return would be compressed into a single line break, and also whether a solution could use a combination of different types of line breaks.
Given that the site is generally pretty lax with whitespace at the end of the line, it doesn't feel unreasonable to allow solutions that use carriage returns instead of newlines as line breaks. The site would probably still need to be able to distinguish between the two because of the quine hole, but other than that there doesn't seem to be much of an issue with this. It's worth considering whether a newline followed by a carriage return would be compressed into a single line break, and also whether a solution could use a combination of different types of line breaks.