That could be improved as described here http://git-annex.branchable.com/todo/tahoe_lfs_for_reals/ ... probably only a day or so's work.
[1] Speaking of jgm have you seen his cloudlib project?
That could be improved as described here http://git-annex.branchable.com/todo/tahoe_lfs_for_reals/ ... probably only a day or so's work.