+1 As one of the dokku maintainers, I would love to see any random issues fixed. Feel more than free to open an issue on our tracker[1] and I'll be sure to comment.
FWIW space processing in command line args is a bit... difficult given our mode of transport (ssh). This is something we're thinking about fixing somehow, though there isn't a great solution yet.
[1] https://github.com/dokku/dokku/issues