Andy D,
Well, the person I was responding to with what you quoted wasn't Kottwitz-Graphics, it was myront.
However, if Kottwitz-Graphics was a client, and I was at his facility, what I'd do is just read a sample of Avery Olive Green (900 supercast), SC 900-765-O into his RIP and give it a name. Then it'd be a named spot color just like any Pantone color.
Then, once I'd profiled his machine, and once the dots his RIP was creating not only matched what his printer actually prints, but the profile I made assured him of getting every single bit of his machine's capabilities on whatever media he was using, then one of two things would happen:
Either the color would be in gamut and he would hit it precisely. Or it would be out of gamut and he would get as close as is mathematically possible to it with that machine, media, ink combination.
So he'd still never have to print patches and chase color again.