I've gotta admit, it is a real nice simple solution. It does require somehow a twin needle carb, otherwise you run into issues with RPM control.

Basically, it is the opposite of what I use for my boat engines that run predominantly constant RPM, where I use the smallest availlable single needle carb, but install a calibrated air orifice outside of the air intake to keep the fuel/air ratio constant with varying load. That orifice shifts the point of pressure-drop when the throttle is opened, increasing fuel suction when the throttle is opened.
But that solution is "not-RC-adjustable". That solution works but is very limited in its application, both WRT RPM and power output.

Yours allows full RPM range and power output. I like it!