Could be an interesting modeling opportunity but I'm afraid it'll never be a viable alternative. The whole thing is based on the mistaken assumption that everyone works in or around downtown Orlando.
The plan for Deland calls for demolishing the existing Landmark station. That ought to be an interesting set of meetings.
Neither Volusia County station is convienient to the 90,000 people in Deltona that contribute significantly to the volume of traffic on I-4.
Looking at the parking, I don't see how they will get sufficient ridership to make it work. The 500 spaces in Volusia (Deland and Debary) would account for about 10-15 minutes worth of the 2 hour commuter rush traffic.
Good news is that the link above will get you to some good details for modeling.