You haven't lived in a home with the supplies on the inside walls, and the returns on the outside walls.
Continuous air circulation does improve comfort with either set up.
But with the older register grille placement. To be comfortable it was almost a requirement(or you had to set the temp up high). As the outside walls always remained cold. And would make anyone feel cold that was sitting close to them(increases the bodies radiant heat loss).
That set up always left a wide temp difference between the outside and inside walls.
You can have any type furnace installed that you want.
Part of customer comfort. Is the customer being happy with their choice.