Hi Jen thanks for posting in the Community! While you can export your Lucidchart document to Lucidspark and vice versa (see this article in our Help Center) there is no live sync between these documents. 

However we're always looking for ways to improve Lucidchart and your feedback is the best way for us to do that. Would you mind adding your idea to our feature request form? Ideas submitted to this form are passed on to the product development team for their consideration.

Thanks for your request and I apologize for any inconvenience this causes you.