Only class instances and links between persistent classes are stored/retrieved from NVS. (Events and timers are not persisted.)

MC-3020 instance storage space is reused. The memory used to store the data for a class instance is moved from and to a "pool of elements" when creating and deleting class instances. Thus, after an instance is deleted, another instance may be created that uses the same physical storage. This poses a challenge when maintain two copies of this data (one in RAM and one in NVS).

If associations are not unlinked prior to the associated instances being deleted, links will be "orphaned" in non-volatile store. As such, this implementation of persistence requires the action language to carefully unlink before deleting.