I am a CA real estate broker and I believe your understanding of the CA DRE regulations is not correct.
You can be the designated broker of record for multiple real estate corporations -- normally those that are related entities, or perhaps owned by the same parent company. In reality, you are not going to find Coldwell Banker and Keller Williams and Re/Max and Prudential, etc., etc., designating the same shared broker of record for obvious conflict of interest and errors and omissions insurance risks. And, of course, being a broker of record, is not the same thing as working in the capacity as an associate broker.
Working as an associate broker is really just working as a salesperson under another broker's license. You cannot work as an associate broker and then claim that you are the broker of record in any transaction conducted under that brokerage. Similarly, besides not claiming you are the broker of record, which you are not, you cannot claim that you are the principal broker of the client just because you have a broker license. In other words, you cannot work under the license of Coldwell Banker or Keller Williams or some other real estate broker, and engage in some transaction, and then claim that the employing broker is owed nothing because you wore your "personal broker hat" on that transaction.
California allows that as a real estate broker, you can work as an associate broker for a real estate company that doesn't do loans, and work for a separate loan brokerage in the capacity as a loan officer -- however your secondary loan relationship needs to be approved by the real estate company.
In any event, if you are in doubt about the DRE regulations concerning agency relationships and the rights and responsibilities of a broker license, you should consult with an attorney to clarify matters for you so that you don't embarass yourself or get yourself into trouble. If you are a Realtor, you can also get some advice by calling the California Association of Realtors Legal Department. Good luck.