Yes, edit-on Pro has an Autosave function. In order to enable this function, you have to insert the <autosave> tag into the "config.xml" file, e.g.:

...

<autosave

  enabled="true"

  method="filesystem"

  destination="c:\folder\myfile.htm"

  interval="300"

/>

...

So the content of the editor will be saved in certain intervals (unit in seconds).

For more information please review the edit-on Pro Integration Manual.