I have been using Craft Prototype since it was in Beta. And it was great. But I never liked one aspect of it.
No support for Symbols.
Craft creates links from one layer to a artboard or anchor. And a symbol is represented as one layer in Sketch. If I have created a navigation bar with multiple icons as links to different pages using symbols, I cannot use Craft prototype unless I detach the symbol, rendering the concept of symbol useless.
I hope there is a fix for this.