Setting up search queries for a nested pipeline follows a different path (prepareSearchForNestedPipelineLegacyExecutor) than top-level pipelines (prepareSearchForTopLevelPipelineLegacyExecutor). In top-level pipelines, we establish the cursor with mongot while preparing the pipeline, prior to calling any getNexts(). In nested pipelines, we establish the cursor on the first getNext().

We should investigate if we can modify the nested pipeline preparation path to more closely match the top-level pipeline preparation path, where the mongot cursor is established prior to any getNexts().