I am a huge fan on Dominican salons. They helped me greatly in the beginning of my natural hair journey when I was living in the DMV. However, I if I were natural, I would not visit often. Actually, once I learned how to rollerset my hair, I didn't go at all.
When they blowout relaxed hair, they don't need to use as much heat to get the straight-straight, bouncy look. I would sometimes get just a rollerset, or a rollerset with my roots straightened only - meaning I wound not let them run the blowdryer up and down my hair.
However, for natural hair, they will likely need to do a rollerset, blowdry, AND possibly a flat iron to finish. If I were natural, I would only go once every couple of months. If you go, you will need to be direct about what you want done - like you have to TELL them what is acceptable and what is not or else they will use a lot of heat.
The naturals I knew in DC went every now and then, or they went and got a simple blowdry and flat iron. HTH