Patching files after install?

[Benjamin]

I am nearing the end of my first ever port, Altera Quartus II design 
software, to FreeBSD. Not so much of a "port" however, as it is just a 
big archive of Linux binaries, libraries and scripts.

I have a question regarding one of these scripts. Every binary installed 
by this program has an associated shell script wrapper that sets up 
paths, and checks the environment. They currently fail when they can't 
find SSE extensions because they are looking for /proc/cpuinfo. That's 
fine I have amended the script, but by which mechanism do I include this 
amended script in the port?

It is not really a patch, because it is applied *after* the install. At 
the moment I am just doing:

post-install:
	@${PATCH} $(PREFIX)/altera/quartus/adm/qenv.sh ${PATCHDIR}/qenv.patch

Is this the correct way to do it? Is it customary to have random files 
lying around in files/ that are not source code patches?

Thanks,
Benjamin