You are missing something, but it isn't hard to miss.

To be totally accurate, it would be necessary for you to have multiple versions of such a chart - one for each tone that needs matching.

The reason for this is that each different scene has something of its own that serves as the most important tone - some scenes have shadows that are most important, some scenes have mid-tones that are most important, and some scenes have highlights that are most important, and no two scenes will have exactly the same tone that are most important.

I would guess that a majority of printers tend to be most comfortable with using exposure to set the mid and highlight tones, and then using contrast to set the shadow tones. It seems to me that most of the VC papers I have been used have been designed that way. You, however, may not approach printing that way, or alternatively may tend to shoot photographs that aren't suited to that approach. If so, most likely you will need a chart or charts that suit your approach and photography.

In my case, I use the charts to adjust the centre points of my tests, but otherwise rely on new tests.