I've been considering doing the same with the helmet vents (cutting out, screening and placing the fans there. However I have more recently also been considering a more "cannon" approach and making vent cutouts behind the blast shield. According to the R1 visual guide that's where the "cooling fans were placed. The screen helmets appear to have a secondary "dust shield" for these vents behind the blast shield. Doing it this way would not alter the outer appearance and would technically be "canon" correct.