PNG 3x export option
XD for now offer just 1x and 2x resolutions in export to png dialog window,
it mean that 2x is enough on screens like 150 dpi, for example Retina is much more thick, so necessary is at least one more option 3x, because on 2x details are blurred.
Retina is pretty popular and png is very good universal format, I can send it everyone and im sure that everyone will be able to see it. SVG is a bit problematic because there is no embed font option in XD... and PDF is great but no proper scale control, in pdf viewer 100% is at least 1.5x too large. So PNG is the one most universal, it will be nice have in XD proper export...
If you select for iOS, you’ll get 1x, 2x, and 3x versions. Hope that helps!
App designed in 414x896. 3X should give the output 414 X 3. This way it helps in exporting screenshots for the app store. Currently 3x is giving the same height and width 414x896