The extension pack does cost and is licensed differently from the core product

I did try that tact, more or less, but the fact is they kept harassing our licensing people and it just wasn't worth it so we removed every copy of it and used something else

And the truth is, Oracle can throw an ungodly amount of legal hassle at people if they want, right or wrong... Just because you're in the right and should win doesn't mean there'll be anything left of you on the other side, and they won't have felt a thing while destroying you out of capriciousness

They're pure evil and even their fully open source products should be avoided like the plague that they are. Hopefully someone will fork them at some point so we don't have to be tied to that shitty company, but until then, better to just leave them alone, because it's just not worth the hassle.