I believe there round ports are way underrated as they work very well low down and midrange to 6500 after that the oval port comes on its own but the majority of the time most work is done under 6k so the round port combined with 1300-1400 is a good balance. Is that the thrift port swirly model head?

Some old rallye guys back in the 90s bought several of my round port weber manifolds saying the round port with some work was better for the dirt coming out of corners. No doubt the oval ports are better at flowing more air while round ports maintain good port velocity at most times but oval ports are better suited to over 1400cc pepped up engines and maybe a stroker 1800+cc with modded E15 crank like Lemonhead was building would see the oval port head on its own.

If I was a tig especialist, Id love to hit the water jackets on a round port by going all the way up fill in the roof, lift the port floor base up, weld some 6mm plates for a unitary rocker cover and fill behind it for some very high position big round ports finally some big valves porting and oven curing by specialist.
That would be the ultimate high round port head :)