The agent's obligation shifts under that arrangement from championing one client's position to providing balanced, factual service to both, which means equal communication, no private negotiating advice to either spouse, and a valuation both parties agree reflects the home fairly.
Where the divorce is contentious rather than cooperative, many lawyers still recommend it, since a shared agent working from one hand-reviewed number is usually faster and cheaper than each spouse retaining separate legal representation, at $800 to $1,500 in legal fees apiece, and negotiating between two competing figures.
The written consent and the agent's actual conduct, not the arrangement itself, are what make single-agent representation work. Get your hand-reviewed valuation from Joel Dyck.