The Classic generators were meant to be as much compatible with the original MCServer-generated terrain as possible, I didn't plan on extending them at all. If you think that your addition is useful, feel free to commit it. I would appreciate, though, if you documented its settings in the wiki - we're trying to make at least the world.ini part up to date 
Note that now that Biomal composition is finished, Classic os more or less dead - I don't think many people would use it, anyway.
Note that now that Biomal composition is finished, Classic os more or less dead - I don't think many people would use it, anyway.