Open BlueDragon supports a compression level attribute for CFZIP, this is really useful for content like jpeg images which don't need to be compressed
Description The compression level to apply when creating a zip file. The range is 0 (no compression) to 9 (maximum compression). DEFAULT:8
update: I decided to add a compress option, which follows the pattern of the filter option
Compress: Optional filter. Can be either a wildcard filter,
e.g. "m*", or a UDF/Closure which accepts the file/directory name and returns a boolean value to indicate
whether that file should be compressed or just stored.