Cameron
Can you send me your contact details and location (Country / State etc) so I know which Time Zone you are in and I will call you to discuss - this type of thing typically requires us looking tat the model / plans / CAD Files etc to give you the best advice.
If you want a Rough direction to go then use the Sideslope Command to design the Laybacks and use the sideslope generated information to build the Surfaces you need for the Volumes etc. I will shortly be posting some new videos on the use of Sideslope from a training Class we recently did here in Colorado.
You can mail me plans / PDFs, CAD Files or VCE Project Files to alan_sharp@trimble.com if you want me to take a look, however we likely need to talk through the details in order to expedite the process.
I have to go out for an hour or so now, but will be back later today - or we can look at this on Monday.
TBC for sure can do what you want here.
Alan.