Something that popped into Juan's head while talking on Twitter. Essentially something that's been talked about forever in VOCALOID fandom is the idea of tones in the software. We already have appends which cover this but they're treated as being seperate banks of the same character.
But why don't we have them come as standard in the core voicebank?
To iterate : my idea is to have a "Core" voicebank which acts as the central/default bank. Appends could then be made to add more tone to the original, or even falsetto banks or any other additional bank for the vocaloid could be stringed onto the core voicebank. When the vocalist is selected then the core bank is the default tone and the user can change the tone to the append bank, which could be an instant change or a gradual change, or even have the banks "blended" together to give an in-between voice (This of course could be in the parameters as well but aye).