Ok so what I found was that sticking to a sens allows your hands to learn movements necessary for microadjustments and general movemwnts on the fly. Once your brain understands these movements you can swap between sensitivities relatively well. This is why you see top players constantly swap their fovs, sens, aspect ratios etc. Their brain understands the basic movements required to get the cursor from a to b. Stick to one and learn the movements!