Maybe sparse files could be dealt with intelligently (not just backup holes as lots of zeros, not extract holes as lots of zeros [but as sparse files]).

http://librelist.com/browser//attic/2014/11/28/handling-of-sparse-files/#0aa400e0ada2cc4ec8656310cff938d1