Open source is generally about the code, not the hardware, even less manufacturing. OSHW (hence the clarification even though a bit longer) is about the hardware and has specific requirements in order to get the label and ID, e.g https://certification.oshwa.org/de000008.html and process https://certification.oshwa.org/process.html
AFAIK there is no terms that means open source + OSHW but I'd love to learn if there is one and apologize in advance if I missed that.
Anyway as I'm interested in the project, which part is proprietary exactly? In theory as they sell via CrowdSupply https://www.crowdsupply.com/apply it should be both OSHW and open source but I didn't dig.