No. Commission negotiations should occur only with a sales agent's broker’s knowledge and consent.
If a commission negotiation comes up between a sales agent and their client, they should tell the client that all negotiations are subject to their broker’s approval.
In addition, the Real Estate License Act says a sales agent may only accept compensation for a real estate transaction from their sponsoring broker or a broker who previously sponsored them at the time they earned the compensation. This would preclude a sales agent from negotiating directly with a client to receive compensation without their broker’s involvement.