I just added something similar to the skarnet.org configure scripts (except for skalibs which doesn't export binaries): the option is named --enable-absolute-paths.
Patrick, can you please test it and tell me if it does what you want? I also scrapped all the /sbin stuff and sbindir. Now all the exported binaries are installed to $prefix/bin by default - this makes it a lot easier to handle that kind of option (only one path to hardcode). -- Laurent