[Limitation] Flattened traced module cannot be consolidated

As mentioned in the title, if a multi-level module is traced and flattened, we do not build nested subschedules but only keep a top-level schedule. Therefore, the inner modules cannot be accessed, and thus cannot be consolidated, since the current consolidation process is conducted in a level-by-level manner.

No files, tests, or entry points are named. Start by locating the tracing/flattening logic and the level-by-level consolidation process, then determine how nested schedules could expose inner modules; done means flattened traced multi-level modules can be accessed and consolidated.

Written by the indexing model from the issue text.