Well,well,well...It depends on how you value sets.
1\You may call it plagiarism. Then...F it shall be.
2\You may accept it as an offer. Then it's a "Back to Classic" set. Other ratings it shall be.
3\Technically, there IS a way to copy things from Xtreme to Infinity, Bigmama... Maybe jluisrf used it, or he went through all the time consumption tasks to make it directly playable in Infinity. Whatever... I don't want to make the guess.
Well, well, well, lets explain:
1: plagiarism would be if I had omitted that these levels are the Xtreme, which I did not.
2: it is about this idea
3: "he went through all the time consumption tasks to make it playable directly in Infinity" -> exactly what I did, brick by brick, script by script, level by level. I tell you that there were times I almost gave up because of the size of the task, but I moved on.