coreboot

If I want to add a large FDD image to the end of my CBFS, and compress it, it's impossible to do without leaving a gap.

cbfstool appears to check the -b address before compression. Additionally -a doesn't seem to accept "end" or "bottom" (I've looked at the source code, and am completely unsure of what -a is supposed to do).

Can -b be fixed to check for space /after/ compression, or
Can -a accept "end" (or a similar flag be created), and calculate the location based on compressed size, or
Can a .lzma file be added in to cbfs, and have it be treated as if it was compressed by cbfstool?

And also preferably could -a be a little better documented.