No, TestOut's Labsim does not currently feature any internal function to limit or specify what elements of the course material can be viewed or when. For now, much like a traditional textbook, we leave it to the instructors to externally communicate to their students what items in the material they are expected to complete and when. If a student has an active course in their account they can access any resource found in that course.
Regarding ways to specify exactly what items are required, some schools' learning management systems (LMS) support learning tool integration with TestOut. These require careful planning and preparation to implement, but some schools choose to set up integrated links that students click that launch the students directly into specific TestOut modules. The links can be selectively chosen and most compatible LMS systems also allow the configuration of due/availability dates for published links. This can be an avenue to assign specific modules, but this would not work to restrict students to only doing the specified modules. More information on LMS integration can be found here.