Can bru's compression be sped up (option maybe?)

[Dan Severance]

	Hi!
	When I use bru with the -Z option to compress the files as it 
writes them to tape or wherever; it spends an awful lot of time trying 
to compress previously compressed files (large, especially) which have 
the file type "compressed data" and other files with the type "data" 
which it may spend a minute or so trying to compress, and then eventually 
writes out the original file.  
	It would be very nice to have an option to only attempt compression
of files that have data types other than "data" and "compressed data".
My bru backups would take a LOT less time, since it wouldn't be wasting
so much time trying to compress uncompressible files..  Is it possible to
have the program check the file types before attempting compression?
	Thanks!
	   Dan Severance
	   dan at rani.chem.yale.edu (internet)