Not being able to reference packaged custom LWCs from other LWCs outside the package
Cross namespace import and communication is currently restricted because of a security limitation in LWC. With our current Lightning Locker architecture there just isn’t a secure way to enable it. The good news is that UI Security team is actively working on a new architecture that will enable secure namespace import and communication. It isn’t a small undertaking and requires significant changes in order for cross namespace communication to meet our strict security standards. The team is about two releases away before we can begin a pilot for customers and ISVs, in the meantime the UI Security team will be active with external communication as we have updates. I’ll follow up here as they are available.