Also, now that code is cheap(ish), I'm implementing UI with a thin-layer of 2D draw commands that can be easily ported (CoreGraphics, Direct2D, Pango, whatever), which is by large the most painful part of it all.
Focus is reliability, UI responsiveness and resource usage, which is why I ditched electron even though it seems to be the only sensible option today for non-ugly, cross-platform GUI.