Since both "/W40" and "/W30" viscosity grades are approved, as long as they are Dexos2 certified, then you are perfectly fine.
So using 0W40, 5W40 and 5W30 should be perfectly fine.
The difference of the low figure (0 or 5) is only relevant for the flow of the oil in the colder temperatures.
0 is officially spec.ed to flow at lowest ambient temps below -22. So as long as you are not using the car at such low ambients, you can use the 5 spec.
On the other side of the scale, the high Temp. range (especially in hot climate / regions: I.E. FL, AZ, NV, Etc.) it is beneficial to use the 40 spec.
Here is an article which, includes a temperature range chart for the various oil grades:
https://fuelandfriction.com/weekend-...ine-oil-today/
An even better one here:
https://www.motorstate.com/oilviscosity-htm/