Workflow: integrating cli/coding with design

I’ve been messing around with ionic 2 from the cli and building/coding apps in a text editor. I recently found ionic creator, which looks great! The only export option I see is ‘ionic start’ with the ability to overwrite an old project. If I want to work with a designer who will work in creator, and I want to continue with the cli and a text editor, is there a work flow for that? Or will creator just do the initial UI work, and I have to reconcile it with an ongoing project via, say, copying new files after an export?
Thank you,
Nate