If you work with your saws for a living there's nothing that says you can't order your fuel lines and other rubber parts ahead of time instead of depending on a dealer.
i have seen those fancy s-shaped black stihl fuel lines fail from e10. they soften and collapse in on themselves. they aren't too expensive even from the dealer and one part number will fit a lot of different saws. you can also go the grommet and tygon route when you replace them. my stihl dealer carries the fuel proof (i hope) grommets.