After a script context terminates only the local variables are cleared up. Any global variables declared in the module will still remain alive.

I assume you're using the CEngine that you've shown in previous posts. The one thing that I saw with it that I think you may want to change is that it is an object instanciated by the script. Thus if the script declares the CEngine variable as a local variable, then the engine will be destroyed as soon as the script ends. You could just declare the engine as global variable in the script, and it will not be destroyed until you discard the module.

Though I think you may actually want to register the CEngine as a global property from the application, rather than having the scripts declare the engine variable. Do you intend to allow multiple instances of the CEngine type, or is it supposed to have one instance only?

Then I suggest you register the CEngine type so that it cannot be instanciated by the script. Register it as a reference type (asOBJ_REF) instead of a value type, and omit the factory behaviour. This will prevent the scripts from instanciating the type, and force it to use whatever instance the application provides.