d&tm wrote:

Are there any single engine airplanes out there that really can go outside
the envelope by burning fuel?

The Bonanza is the big example that comes to mind.

The moment of the Fuel is forward of the main spar and as you burn your
fuel off, the CG moves aft.

If you have the 5th and 6th seats filled or have lots of aft baggage,
you can end up aft of limits, which can bite when you are low/slow on
approach.

Dave