I happened to have some samples of Noodler Black on Clairefontaine paper. I agree with antigone's comments that it does smudge with a highlighter or a wet finger. It appears that there is a layer of dried ink that has not "attached" itself to the paper that is easily smudged. To me, there seems to be more "loose", smudge-able stuff with Clairefontaine than with other paper.
I have not tried any of Noodlers highlighting inks, but they appear to highlight without smudging based on the samples shown on the Pendemonium website. Maybe you should make an inquiry with them. However, even with those, there may still be a problem on Clairefontaine. Here is a link:
Pendemonium: Noodler firefly inkAddendum #1: I just did a quick side-by-side using Clairefontaine French-ruled compared to standard office copier paper. Here is a scan. It appears that the smudging is comparable in both. The highlighters were two colors of "Sharpie Accent". The yellow marker actually picks up a lot of the ink on its tip and starts highlighting in a black smudge everywhere. (I also cut and paste in a blow-up of the word "Clairefontaine".) The last line of each sample was smeared by a wet finger.
Addendum #2: PLEASE don't interpret this post to mean that there is any "problem" with using Noodler Black on Clairefontaine. Far from it. I use this combination all the time. To me, there is smudging to some degree with every ink I've ever tried. Now I'm going to have to get some Noodler highlighting ink just to find out how it behaves and if, somehow, it doesn't "smudge" in this situation!