For training, I prefer using a version with a translation.
I guess that the rules forbid using something else than the Japanese version because the length of the text affects the time the run takes ? It remains forbidden even if the language patch increases the duration of the run ?
If I got a time good enough to be competitive, I'd certainly run with the original version to gain some more time, but if I'm at +50% of the WR I wouldn't worry much about losing three minutes more to this.
The translation is banned because it's not an official version.
You're more than welcome to do runs of it if you don't want it on the leaderboard though.
Considering that the language translations are listed just below the main download on cavestory.org ; some of them hosted there ; I would not really have thought them unofficial despite being community-contributed.
Anyway, thanks for your answer.
