The N20 doesn't have such a system but my 6.0NA and my 5.2 did. I don't clearly understand your problem. The "Nacra Rudder Alignment and Crossbar" kit won't fix any interference issues but are to allow you to adjust the alignment of your rudders. It should function exactly the same way that the solid bar with two holes worked....and the adjuster should only be installed on one end - it's not necessary to install two of them.

If you could post some pictures of the actual interference problem, we could probably help you more.