Personally I think full synthetics are just hype Ted... and lighten your wallet accordingly. My, hot running (222F oil) supercharged, Verada specifically states you are NOT to use full synthetic but a blend of petro base and synthetic. The 4 stroke Honda or most others need nothing but the engine oil you put in your old car. From the manual
The viscosity index (weight) indicates the flow rate of
the oil. For most models Honda recommends a 10W-30 or
10W-40 viscosity oil that meets API service classification
SG, SH or SJ. This weight and grade of oil is suitable under
most operating conditions.