Hi,
I like speedy and efficient preprocessing of data with disk.frame. Would be cool to be well integrated with efficient online learner vowpal wabbit.
i.e.
https://github.com/denik/vwoptimize
in the sense of providing an integrated way to dump disk.frames in vw readable csv and maybe even call it via reticulate? that would likely be more in scope of your disk.frame.ml package, though.