AC is my business
Yes, increasing air flow across the coil will reduce head pressure, thus reduce suction pressure making the air colder, to a point. I'd like to see accurate before/after air flow readings, not "modeled" with a little 12 volt fan. CFM and static pressure (that's the pressure loss across the louvers he's reducing) are not a linear relationship. The proof really is in the reduction of head pressure and there is no before/after reading.
I found a big installation error on my last rig and this reminds me to check this one. When they installed the ducted conversion on my last one they did not seal the supply and return plenums properly, meaning a lot of air was just short cycling between supply and return, not getting to the space. Took some foil tape and sealed between the two plenums and it helped A LOT!