Thanks for the ressources. It's something I will try to consider in the future. 😂 Somehow my todo list gets not much shorter....
I am not a pro on Qt development, but you might get a lot of this for free if you use the built-in UI elements. The new Bitcoin Core App will also be built in Qt (QML though), so there might be an opportunity to collaborate. https://bitcoincore.app/
Did you check out the docs? https://doc.qt.io/qt-6/accessible-qwidget.html
As for testing, it depends on your OS. MacOS has a great screen reader built-in, not sure about the others. We have some info and resources in the Bitcoin Design Guide. https://bitcoin.design/guide/designing-products/accessibility/
Discussion
I have a hunch that AI is a great helper for this task. Did some quick tests over the weekend, throwing code at ChatGPT and asking if it's accessible and then telling it to make it accessible, and the results were very good. It might not be a heavy lift.