That's certainly my last resort. I wish there
were a more standardized
format for binary patches (I don't think a universal diff will cover it,
except for the case of hex files).
Would definitely be nice if there was a more standardized format.
In the absence of that, pick a tool that's relatively widely available
(xdelta, maybe?) and use it. Or write two trivial programs, one to dump
a file in hex, and one to read such a hex dump and turn it back into a
binary file. Then you can distribute garden variety text diffs, and the
source code for the two little programs.