Why this little bit of styrofoam?

There is this small strip of styrofoam that blocks part of the evaporator that would blow air out the vents on the passenger side. Is this to help balance the flow between the two sides?
Should it be placed or taken out?


Thanks

Years ago my wife would complain of being too cold because more air is directed to the passenger side. I inserted a piece of aluminum strip to redirect airflow to the driver. It helped.
Glenn
70 E

I balanced mine by a partial blocking the one opening and extending the baffle. Initially this directed to much air flow towards the left side and starved the right. I cut a hole in the baffle extension and by tuning that got a nice balance.