Hey Ryan,
Sorry to hear that you had a negative experience.
Designated dual agency is very common in NC and in most cases allows both buyer and seller to receive the highest level of service with no conflict of interest even though they are being represented by the same Firm. Unless your agent is affiliated with a small Firm or works in the same local office as the listing agent, the odds of them knowing each other and having already shared info about either party with each other are pretty slim.
By not allowing designated dual agency you could be preventing yourself from purchasing a property that otherwise checks all of your boxes. For example, I am an agent with Real in the Triad. If I were representing a buyer who indicated that they do not consent to dual agency, I would have to filter out all of the listings from every other agent affiliated with Real to make sure that we avoided a transaction with agents at my same Firm. That said, I highly recommend checking the box on your buyer agency agreement stating that you do not permit the same agent to represent both buyer and seller.
Jayme