If you want a programmer designing the interface, sure anything would work. Just make sure the comp times are low ;)
Now, if you want someone else to jump in and be able to use templates or style it.. Wouldnt be better to use a known markup lang? I mean, outside Microsoft (Silverlight/WPF), Xamarin.Forms did well (until they bought it). Avalonia seems to be rocking now in the dotNet community which also uses it. There are more cases like Noesis GUI. My point is that it is a well known-stablished markup lang. I assume there are editors out there that you can fork/extend in vnext
