@thephd Well even in theory it doesn't makes sense, of course xxd is going to be horribly inefficient (hexadecimal isn't an efficient format, parsing C arrays is complex, …).
And xxd is also not a really standard tool so I've seen my fair share of integer-array blobs where you just hope that you're never going to have to modify it because there's no recipe to build it again.

Also another way I've seen for packing arbitrary binaries with executables is concatenating a zip file afterwards, self-extracting zip style, which is probably horribly inefficient at runtime.