3D WBS method goes further of project structuration, I call it then 3D Project Management. It is 3D structured projects with advanced project management methods.
For the EVM S curves, I recommend to use paid costs (and not commitments or amounts of invoices received), with payment terms and conditions assigned on schedule’s tasks, in order to obtain the cash out curve. Because, with the cash incurve, it is easy to obtain a cash flow curve linked to the schedule. Therefore, the planned value curve is function of the payments, plus the hours spreaded on the schedule’s tasks. No need to assign resources on tasks, a weight in hours is enough.
Regarding the Earned Value calculation, I recommend to put in place intermediate milestones method on schedule’s tasks. Each milestone has a weight so that if the schedule has no delay then the theoretical earned value S curve is equal to the planned value curve. So, if the schedule is over-time, then there is a variation between the Earned Value and Planned Value curves.
To be noted that Actual Cost curve extension gives the cost estimate at completion. And the earned value curve extension gives the final date estimate. At the intersection, there is the final point of the project.
To be noted also that the planned value late curve is on the graph and is calculated with the schedule.