Hi Ted.
Welcome to the forum.
Firstly, some don't rate the oil separation as important as others. I think it may be important, so I like to see at least some.
At the end of the day, I suppose it all depends on which bases you've tried and whether oil separation should be expected, as the recipe says.
If the recipe says the oil should start to separate at a particular point, then generally that's what should happen.
SnS ;D