Abstract
Open superposition describes a common pattern of collaboration in open source software (OSS), in which contributors make small, incremental changes that accumulate without requiring extensive coordination. This study examines the boundaries of open superposition in corporately engaged OSS projects by analyzing more than 160,000 pull requests (PRs) across gRPC, Kubernetes, and Zephyr projects. While most PRs followed the expected pattern of small, layered contributions, these incremental changes did not account for the majority of code evolution. Instead, the bulk of changes, measured by lines of code added, lines of code deleted, and files modified, originated from a comparatively small number of episodic, large-scale PRs that we characterize as "episodic large-chunk development" Our findings show that open superposition remains a dominant mode of collaboration in corporately engaged OSS projects, but it coexists with complementary development patterns that enable coordinated, large-scale work. Recognizing these episodic, high-intensity contributions offers a more complete understanding of how complex software is built in modern, corporate-influenced open source ecosystems.