With the majority of Designers using MacOS I think a better strategy would be to get the MacOS version fully baked first, and only then using your vital resources on translating across to Windows. To sway practitioners across from Sketch (who are MacOS only) you first need a solid product with at least a basic feature, which right now is still lacking in XD (i.e. flip image). I know this sounds harsh to Windows users, to which I apologies, but being realistic there is no point having two half finished products on the market, as you are useful to no one. Instead, go with the majority first and secure the core user base. It is frustrating to know we the majority have to wait months and possibly years to have simple fetaures added because resource is stretched thin working on Windows as well. The big risk in Sketch, Invision and Zeplin bed in and run away with the market.