All targets related to "the old" mirror-maker thingy (building that huge makefile) are slated for deletion right after 5.1 is done.
So far, dpb -F is the new and much better way to do things. We've found no drawback so far, faster, cleaner, more accurate, you name it. So, if you use the old mirror-maker for any non-trivial purpose, now is the time to adapt, or explain to me why you can't...