Attic Heat Remediation (Foam vs. Radiant Barrier)

Hi all! We have a 1930's Tudor style house. Recently an HVAC company installed ductwork and an air handler in the attic for central AC. It runs 24/7 and cannot keep up with the heat. They have been out here five times and have the data to show it's sized correctly, return and exchange temps are perfect, and it's functioning to spec. Still, around 4PM EST it starts to fall behind bigtime and can't recover until around 4am.

I would have not let them install the handler in the attic or gone with mini splits if I knew this was going to be such a useless system. Problem is, and they don't want admit the system is not the right design for the house.

I've had two energy / insulation contractors take a look and they offered very different approaches to help but both kind of seem to make sense. I was wondering if you could weigh in. Our attic is unfinished and roof is 18 years old but in really great shape. We have a ridge vent but that's it. The attic floor has some ancient pink fiberglass insulation under it.

1. Close off the area by the eaves and spray 2" of closed cell foam on the roof.

2. Install a radiant barrier and attic roof fan in the middle of the tunnel the barrier would form and vent air over 110 degrees.

I've heard on old homes it's better to let them breath than to seal them up but also keep reading that foam insulation is amazing.

Really at the end of the day we need a cooler attic so our air handler isn't so stressed and heat transferring to the ducts. Thank you so much for any help you can offer.