+1

Never seen it separate, since the fuel was used within a month or less ( I assume that is the case for most of us )

I used the last 1/2 gallon out this can that was seating for about 1 years, all was normal and I didn't see any oil left in the can and the fuel had its usual thickness and to top it off I didn't shake the can before using it.

So, there you have it, I say shake it if that makes you feel better

Smoke oil, that is another story