How effective are the under dash AC duct outlets on a original car?

Professor Fate said
If you really need some outboard vents, you might be able to tuck some smaller diameter hoses along the underside of the dash and use some underdash vents like these from Classic Auto Air at the dash ends. Just tap the hoses into the factory center vent. That way you could avoid trying to fit hoses around the instrument cluster, radio, HVAC controls, wiper linkage, and glove box.
A/C Vents | Classic Auto Air - Air Conditioning & Heating for 70’s & Older Cars & Trucks.

Those are what I am really trying to avoid. If I was going to do something custom, I want it to look somewhat integrated, and those to me look too....JC Whitney? I like the stock look because it is stock, but would want custom ones to look like maybe the factory could have done it that way.

I plan to do some home engineering on the whole thing anyway and am going to try and use a Ram heat/ac box. I know it will probably be visible under the dash if you look, but I like the idea of using the stock under dash vents as long as they work ok since it is simple and looks factory as long as you don't look too deep. If the stock vents didn't work well then I would go looking for ways to integrate vents into the dash. Based on the input here, I'm leaning towards just using the stock piece and see if I can get it connected and working.

I wish Mopar had done vents like the Chargers and such. But they didn't.