I had put 495 flights on my BME engine with Amsoil mixed at 95:1.
Never had a problem. Engine was adjusted lean on the idle and rich at WOT.
I know it was lean because a 1/8th turn would cause the engine to hesitate and sometime cut off with fast advance of throttle.

It had the idle down problem consistantly and was very noticable. Now I had it rebuilt to a 105 and using lawnboy at 32:1. It is rich on the idle and just right at WOT. Other than the shakes, and the loading up with long idles, then engine runs great and is stronger than it was before. Definately more RPM at WOT. It still has the idle down issue but not nearly as bad as before. I think if the idle jets were opened, it would help to eliminate this problem. I will not do that. I have gotten use to it and just work around it.