1367b does not allow for supplemental jurisdiction over claims by plaintiffs. 2361 provides for nationwide service of process. 28 USC 2361 empowers court to enjoin. Tashire makes clear this is matter of trial judge's discretion. Insurance policy should be significant aspect of litigation before plaintiff's choice of forum is denied.
Intervention is flip side of necessary party analysis.
North Carolina Casualty. In its absence it may be affected as a practical matter if its insured, Alice, is liable for large judgment.