Oil goes into "perfect" solution when it is mixed with gasoline. Gasoline mixed with too much oil will smoke more and it will burn cooler which is why it fouls the plugs. But it is NOT a lean burn issue because if it were a lean burn issue, the machine would burn much hotter and that's when you burn a hole in pistons and have a general melt down. 2 Strokes don't like too much heat.
The oil does burn at a steady rate. But the engine has to be running at the right temperature to do it. Too hot...melt down...too cold not enough oil is burned and this isn't quite as bad and a hot condition but it can foul plugs and gunk up the pistons.
While the 2 stroke can run under a very lean condition which modern state of the art machines try to do to keep within emission standards, too lean is bad for them as it always has been. But if you run pre-mix with a GOOD oil that has all the required certifications, you should be able to run at 50:1 under all normal conditions without fouling the plugs or gunking up the pistons and still get all the power the machine is capable of producing.
Just don't run the machine with less than 50:1 or use a poor grade oil.