speeding up git-svn when directories are copied?

When importing a whole repository, git-svn currently takes a _lot_ of time. Almost all of it seems to be spent getting the full text of each and every file when a tag or new branch is created.

If I remember correctly (but it was quite a while since I looked at it), git-svnimport didn't ask the Subversion server for all the files; it just noticed when the server said that a new directory was a copy of an old directory, which makes them just as fast as any other commit that doesn't change a gazillion files. (I've had an import running for a few hours now, and have checked on it about a dozen times; every single time, it was importing a new tag or branch. This suggests that making these go as fast as regular commits would speed up the import by more than a factor 10.)

Have you looked at doing this with git-svn? If it's not on your to-do list, I might take a stab at it at some point. But I only speak the copy-n-paste dialect of perl, so I'll need to find a largish block of uninterrupted time first. :-)