Easel now offers the ability to export an archive of your project. To use this feature, choose Download ZIP from the File menu in Easel:

When you choose this menu option, you'll be presented with a popup asking if you want to export all workpieces, or just the active workpiece.:

From there you can click Download ZIP file to download an archive of your project.
The archive contains information about your project in a non-Easel format. When extracted, you'll have the following files for each workpiece:

This data could be used to carve your project in another tool, if desired, or just give you peace of mind that you have a local copy of your work.