Hey Danny, it sure does a good job at that. The finger spacer is fairly wide. Also, the edge of the aluminum plate butts up against the string. This squares your hand to the string and helps to stop that index finger from hitting the nock. Your problem could be too much angle on your forearm, elbow, or hand. The tab helps stop that. All in all, the tab is well thought out and designed to force you to have proper string hand form.
However, unlike Papa I've always ordered the finger spacer separately. As he suggested, maybe it's something new they're supplying and worth asking about.
After shooting the tab awhile, you will see a definite demarkation where the string leaves the cordovan. Trim the excess cordovan to that line for an even cleaner release.