Yeah... you are running a considerably cleaner mixture than he is... and at 50:1 I'd think that's synthetic. (Though not for sure about the Stihl brand)

There's no problem running it... it just takes a little longer to fully break in... many fellas don't even bother with break-in and just run what they intend to run all the time.

As long as your engines needles are tuned for good idle, transition and peak rpm minus 100-200 you are good to go. (this is of course using a prop within the recommended range)