Guess that answers my question, or not: "In particular, the Mediation Plan requires the presence at the mediation conference of all parties, corporate representatives, and any other required claims professionals (e.g., insurance adjusters, etc.) with full authority to negotiate a settlement."

"....all parties, corporate representatives, and any other required claims professionals (e.g., insurance adjusters, etc.)"  suggests all in attendance togather.

"....with full authority to negotiate a settlement." suggests a single settlement, not four unique settlements, thus separate meetings.

SGE