Previously in ES e3 and earlier version of ES, you may just select the single run object and click on Input C tool button and hit the "Enter" key to convert a single run object to an Input C object. It does not work like that anymore in ES e4.
In ES e4, all you need to do is to click on the Satin Stitch button in Outlines toolbar to apply Satin to the single run stitch object. Please see screenshot below:
You may simply select the line type of object and then click on one of the stitch types in the Outlines toolbar to switch outline stitch type from one to another freely.