Interesting work! I'll have to check out Furnace - looks like it has some interesting capabilities around wave automation from what I was seeing of the corrscope outputs.
Viewing post in Seeing Red jam comments
Furnaces does have a versitile wave synth but that requires the wave RAM to be freely accessible. Guess which system only allows wave RAM writes when all of the channels are disabled?
Because of this, the common strategy is to stick with the 5 wave RAM slots you initialised the song with. Each of the channels (excluding noise) can freely change which slot to use - I simply used 5 "pulse widths" for this OST.
The noise channel's periodic mode is abused for extra bass as well. Did I mention that the lowest possible note for the regular channels is D#2?
That's about it for my rambling. I'm glad my songs piqued your interest in Furnace!