Re: Better to port ?
Most of the time you don't even port to ARM. You port to UWP and recompile for ARM.
And that's what I'm not going to bother doing for my WinAPI applications. At least not yet. I will port them to a cross platform UI (my own) and when I have that up and running (and ported to macOS and Linux), then I will port the thin platform specific layer to UWP.