The Boots of Blinding Speed are not used in Morrowind speedruns. The high speed is achieved with a weapon swap glitch(only present in the 1.0 version of the gam

The Boots of Blinding Speed are not used in Morrowind speedruns. The high speed is achieved with a weapon swap glitch(only present in the 1.0 version of the game) where swapping between two weapons quickly will apply all of their buffs permanently to your character. This is done with two story related artifacts that happen to buff all sorts of useful stats, including movement speed.