I have ran regular oil and synthetic back on several vehicles and done several combinations. When cleaning out slush on a recently purchased used one, I would often perform engine flushes and run regular oil after and a filter changed, then switch to synthetic and new filter without issues. That's air-cooled and water-cooled. If the seals are good, it doesn't matter that you throw at it. As said before, unless specific to a motor build, buy you know and feel comfortable with.
Playing with synthetics and engine oil change intervals can be fun, and expensive as well.
Playing with synthetics and engine oil change intervals can be fun, and expensive as well.