I did my first port match on the intake that I'm running on my car now. The above sounds like an easier option but, I used some Hylomar when I prepared it for the port match. If I can remember right, I used blue on one side and red on the other. Drop it straight down, bolt it down, remove and you have a perfect outline of the intake port of the head on your intake. Scribe it and grind away. On my intake, I tried to blend the match as far up in the ports that I could but, it was also a stock piece. With an aftermarket intake, that is already pretty good by design, it would probably be less work and take less to blend up into the ports.
Who knows what kind of gain it will make, back to back testing would be required to really determine that but, if done right, I can't see how it wouldn't be worth something.