Metroid II, Prime Get New Speed Run Records
PrinceBrightstar writes "Both the Metroid Prime pure speed run and the Metroid II 100% completion speed record have been shattered by Zoidi and Brightstar (myself) respectively. The Metroid Prime (GameCube) pure speed record is now 1hr 17mins, and the Metroid II (GameBoy) 100% is now set at 1hr 12mins, with further decreases planned - these records were recorded into video form and no emulators were used." We've previously covered Metroid Prime 'speed runs', which are an extension of classic Quake speed runs.
The previous poster listed 15% items without the ice beam. Your method would require getting the ice beam in order to skip the speed booster.
Because the effects of changing a few polygons is much easier to run thru QA than the effects of changing the properties of one of the most important player abilities.