As an experiment, I saved a single slab as an object and examined the autoscript. There are a lot of group commands, and I did find and replace to give them human-readable names. The now legible structure was surprising:
The geometry is in Group A. Group B is defined as placing Group A. Group C is defined as placing Group A as well. Then Group B is killed without placing it. Group D is defined as placing Group C. Then A and C are killed. Finally Group D is placed, then killed.
None of this is needed since there are no operations. I understand that the autoscript routines must be ready for anything a user might save as an object, but this seems excessive and strange! It’s mostly my curiosity, but can you tell me anything about the reasoning behind this?