For that application, would not full-aperture ball valves be
appropriate?

Yup. I use one in my Jodel now; they work fine, but a weak point
appears to be the o-ring around the shaft. The ball and teflon seats
work OK. Watch that you don't get a really poor quality Asian unit;
there's a wide range of stuff from good to pretty lousy out there.
Badly cut pipe threads and all.

Dan