Serial.print("That's where I'd like to display the BSSID in some way that's reusable... if possible.");
I don't understand what you mean by "display the BSSID in some way that's reusable". BSSID is a pointer to some memory where some data is stored. Pointer can be treated as arrays, if you know how much data is there, or if the data has some known terminator (as a NULL is in a string).
According to the documentation, bssid is a MAC address. MAC addresses are 6 bytes.
But, BSSID is a pointer, and the config.bssid is a pointer, so you can simply make config.bssid point to the location that BSSID points to, and let the software that uses config figure out how much data is pointed to.