Raising the exhaust port on a 2 stroke raises the horsepower, but the more you raise the exhaust port, the more you lose low end performance.
Would it be possible to have a mechanical device that could alter the exhaust port height as the motor moved through its rpm range so you had the best of both....better low end performance along with superior top end performance plus more horsepower?
Seems impossible!
NOT!
Look what Yamaha did with their 2 stroke motorcycle engine.
https://www.youtube.com/watch?v=2vqrMzbDsic