This advanced engine option controls whether the current project should continue to run while a new one is being loaded. It's enabled by default. Enabling this option reduces downtime (i.e. frozen output) while switching between projects, but at the cost of increased memory usage: during the transition, sufficient memory must exist to accommodate the current project's Freeframe instances and frame buffers, plus the new project's Freeframe instances. Disabling this option conserves memory, which can be useful when working with large frame sizes.