Question is the Japanese version really only 24 seconds faster than the English version? Which brings me to ask is the English version fully optimized as in can't be done faster?

Japanese is 5-6 minutes faster than English, 2 puzzles in ToS have been shorten/removed in the Japanese version. So the current World Record is in fact less optimized than the 2nd place run.

English can go lower than 4:40 with a really good run. I think my SoB was around 4:35 with the English version. Japanese is mostly faster from the puzzles missing that Stovent said. My run was basically all red splits until Tower of Spirits 6, which I was ahead for that. Hasn't gotten much love since then really, so the times look like they are close to each other.