Off idle bog

I agree with @Hysteric , in that you are probably too far down the transfer slots.

The easy check is to do as he says, and I would increase the idle speed ~50 rpm atta time until the sag disappears, then report back.
If the idle speed goes up too high, retard the timing ~3 degrees atta time, to slow it down; for this test, do not use the speed screw to slow the idle.