And, Yes oil ratio does effect the amount of fuel moving through the jets thus it does effect carb tuning.
As for oil being designed to burn in modern oils. Yes, that's true, but let's talk how that happens in a perfect running engine scenario.
When the intake port opens gasoline and oil mix in fine droplet form enters the engine. It immediately it meets hot engine parts and the fuel is vaporized dropping the oil onto the parts of the crankcase. As the piston closes the intake port the fuel in vapor form moves up through the transfers into the cylinder where it can be combusted. A little liquid oil from the surfaces of the crankcase moves with the vapor, spark plug fires and the whole works combusts. Now, if a fluid enters the combustion chamber it can not combust, it has to be converted to vapor first. Tuning or jetting is a measure of how much vapor is in the combustion chamber at the moment the spark plug fires. The oil in the combustion chamber at the moment the spark plug fires is coating the surfaces of the cylinder wall, chamber and piston dome. Some of is burnt immediately AFTER, some takes the ride around for a second or third go around and some is expelled through the exhaust port.