With the last (February) ISO some work was already done to get Calamares to work with QML modules (used in KaOS is the notesqml module).
That QML work is now expanded to the Welcome page, Locale page & Keyboard selection page.
Keyboard QML is not used in KaOS yet, but for welcomeq & localeq quite a bit of KaOS code was accepted upstream.
Complete new (and not presented upstream yet), is moving the Locale page to show a globe based on Marble code. Neither welcomeq or localeq are ready yet for production use, so probably won't make it in the April ISO, but here some images to show what it looks like now. The Marble globe is fully interactive, you can zoom in/out, rotate and so on. Images also show the navigation buttons (back-next-cancel) in QML.

8 days later

Localeq has moved from Marble to QtLocation, connections are working, hovering mouse over the map shows coordinates: