It is well known that castor blended fuels provide better protection to higher temps.
I can see if castor blended fuels are hard to come by where you are then full synthetic and carefull watch on your engine would suffice.
For me caster blended fuels are readily available and cost are equal to full synthetic so its a no brainer. I will use caster blended fuels.
Wiping the plane down after flying is a non issue.