I understand this is a complex feature but it will be really cool and will cut hours of efforts to minutes.
As Visily is ai driven so it can understand and convert UI website design for pc to mobile. Some of the key things will be like compressing the options in menu tab to shrinkable button as in most of the mobile websites and shrinking elements in similar ratios so that they fit different screens.
It will not be possible to convert a design completely but if Visily is able to do some of it and give something to begin with instead of making two different designs from scratch, it will be real help.