WAI-ARIA role="tab" incorrectly implemented in Dingus

The role=“Tab” of the links of the Dingus, which is used to select the rendering mode of the preview, should be changed because it is not correctly handled by screen readers. There are three tabgroups with one tab each.
This blog post may be one solution. The problem is, I can’t see how a tabpanel could be implemented for the “preview” tab.