If the issue is that oil needs to be thin enough by the heat to flow in the engine, wouldn't it be better to replace it with an even thinner W oil?
Well, actually, no.
SAE number does not denote "thickness", it denotes oil's flowing characteristics under certain conditions.
Using the "thinnest" fully synthetic or polymer oil is a great idea for modern turbo charged engines made with space age modern materials, especially in extreme (very cold and warm climates, high loads).
Using very simple and cheap dino oil that is also "thick" may be a great idea for simple and older (mileage-wise) engines because it may enhance compression compared to high tech oils and it will be easy on some parts of the engine that might be influenced by high tech oils and additives.
We spoke here only about SAE values so far.
Oils have also a number of other specification they have to adhere to. Oil "quality" is not being read out of its SAE number, but much more from its API gradation (S or C, for gasoline or diesel engines).
Furthermore, there is a number of special additives in oils that cannot be read from neither of these values.
I would say that ANY Kymco scoot will hapily drive forever on semi-synthetic 10W-40 API SG oil or higher if driven 10 seconds after it is started, outside air temperature being from -30 C to +50 C, regularly changed every 2-4.000 kms or once per year, whichever first. This is what every Kymco scooter driver should know about oils and that's it. Everyhing else we spoke about is "anally retentive", as our colleague once said.