Good luck with that goal, after Longhorn went down, all its design ideas were resurfaced as COM, and since Vista, COM (alongside with its WinRT makeover), is the main API model in Windows.

Raw Win32 C API is stuck in Windows XP view of the world, with a few exceptions in some subsystems.

Yes COM tooling sucks, which is kind of sad given that it is the main API model in modern Windows, but I guess WinDev suffers from Stockhold syndrome.

AddIns are only moving away from COM, because otherwise they wouldn't work in your browser, so you get to use JavaScript and TypeScript instead, and on native Office they run inside a Webwidget, hurray for performance.