yes and no; i wrote the song on openmpt before, but transcribed stuff by hand (mostly). you can probably see that the code is easy to adapt to other songs and
that's what i did (not 100% tho, this has one or two techniques i didnt use on bossabeat).
i agree that it goes against the kind of experimentation that bytebeat is supposed to bring, but that's why I'm not making any converters for it (and if i do i probably won't release it); having such a thing would demotivate people from experimenting and coming up with their own, more interesting ideas.