Not the author but I’ve noticed that when it come to Tk, by modern they usually refer to the new widgets released in version 8.5. Tk used to have a very distinctive look and not-native. With the new widgets it is a look closer to native look

There are some on Wiki: https://github.com/phase1geo/tke/wiki/Bird's-Eye-View

Which let's you know what you can expect. Also the wiki seems rather good.

That was my first reaction. I tried clicking the wiki link, though, at the top of the github page, and from there to "Bird's Eye View". Pleasantly surprised.