The ‘PAD’ tool, can be set to thickness and uncheck ‘hug terrian’.
This example has a 6′ grade change. I add the PAD set to 6′ high. You can add as many nodes as you want while inserting but cannot add node after it is completed. So, make sure if you have an odd space to ‘fill’ you add enough nodes.
I then set the PAD to match the height needed to create a fill at the wall.
‘Curve’ is also possible with a PAD.