Sorry for the late reply, I'm new to TASVideos and didn't realise this page existed. I experimented in the first level with different sound settings, and the music was definitely the worst offender. Music added around 5 seconds to the time it took to finish the level, while sound effects added 10-15 frames, so from that we can extrapolate that turning off all sound saved 40 seconds give or take (almost definitely give considering the first level doesn't even have a zord fight). Honestly keeping on sound effects wouldn't have been the end of the world, however when I started making this TAS I hadn't even considered publishing it and only wanted to see the game beaten as fast as possible, entertainment value was not really on mind.
It really is a bummer though that the music lags out the game so badly, I genuinely really like the soundtrack and considering the games very small playerbase, a silent film isn't exactly going to encourage people to play it. I'm not sure re-adding the level music to the video would be allowed but it would be something to make it a little less lonely.