From my limited understanding of the theming system for KDE applications on Windows, the application needs to expose a drop down menu with a list of themes so that a user can switch to their desired theme. Even if we linked a disabled version of the library and enabled it in Craft, it wouldn't do anything since the application needs code to display a list of themes and a slot to change the theme. Given this requirement, I see this as a compile time option where an application must opt-in, link to KF5BreezeIcons.dll and add the code displaying the theme list. This is based on my understanding of how Kate handles themes. I have not looked into any other application. There might be a more generic way of changing/configuring themes for KDE applications on Windows that I am not aware of.

I've tested this patch since I'd really like to use Kate with the dark theme on Windows. I built Kate on Windows using Craft, added KF5::BreezeIcons as a dependency for the kate-bin target, and set the QIcon theme name in the KateColorSchemeChooser class. This did not work.