My vents I put towards the wall, open them… Also, you can get black dryer vent hose, 4" or 6" hose, and bring it out one of the access holes, form an “S” with it and light wont travel past the corners. I have dryer vent hose propping open the bottom holes anyway…
Input must get close to output to better airflow, and with the other vent hoses in place, you have negative pressure pulling fresh air in, but not the walls…