The Yak 52 has automated mixture control so no cockpit lever - and I certainly never missed it. I would miss the prop lever, however. That big paddle prop in fully fine with the throttle closed makes a great airbrake and allows *very* steep approaches. And if you need to go-around, you're already in fully fine.
And the '52's aeros power setting is full power power at 82 percent RPM (why 82, I wonder??).
Cars have complex but reliable electronic control systems with fuel injection which eliminates carb ice and ensures the mixture is always optimum and the tickover rpm constant regardless of ancilliary load. But aero engines are simply are not produced in sufficeint volume for such developments to be commercially viable.
SSD