Another vote for prioritizing a name change. Why create continual confusion and awkwardness for the thousands of people who will want to use your product alongside Sketch the design app? (That's me saying this is an awesomely useful project, BTW.)
I'm just imagining describing the Sketch/Sketch workflow to a non-technical manager... ;)
How about calling it "Expo Studio" or "Expo Easel", which have similar connotations?