1. Cast Members/Employees are allowed to park anywhere in new garage and all surface parking(excluding valet lots). I believe there is a rule allowing use of 1st/2nd floors of Orange if shift is before 2PM(memory is a little fuzzy on that one).
2. Disney does not have a vehicle registry for Cast Memebers/Employees(excluding company owned vehicles).
3. Disney cannot use the Florida state-related License/Registration system for something like CM/Employee parking lot enforcement. The company has to have a really good reason to look up plates. I have personally heard many requests denied.
4. Company Management will occasionally stand at Garage exits into Springs to find CMs/Employees who are parking in the garages. That is how they would audit staff. It is obvious when people are in costume, costume under clothing, and/or visible company IDs.
5. It is possible for the garages to use plate readers for crime prevention/apprehension reasons like any of the billion cameras on property.
Reality is that they would be losing a lot of staff if they went hardcore on parking enforcement. It has been a long time since I've been at Springs frequently but you're more likely to see a higher amount of non-Disney employees using the wrong parking location than Cast Members.