If you use a plane, I'd suggest setting the blade VERY shallow, as it will try to bite into the Ivroid deeper than you have it set for. In other words, set it low enough it takes several passes to get what you'd normally do in one. If it grabs and digs in, you won't be at all happy with the divot it leaves.... and I'd skew cut instead of straight cutting it too.
A really sharp plane can do a really nice job, but be aware, it is not the same as cutting on wood.
My wife says I don't pay enough attention to what she says....
(Or something like that...)