I successfully built a simple dualRole BLEuart simple sketch allowing me to connect as Client to a server and simultaneously be connected from a Client to my esp32-s3 as server as the one from Nordic on the nrf52 devices.
There is but a little glitch.
I use these callbacks for connection state:'

//BLE Peripheral Class
class MyServerCallbacks : public BLEServerCallbacks {
 void onConnect(BLEServer* pServer) {
 Serial.println("Server connected to device!");
 deviceConnected = true;
 };
 
 //BLE Central Class
class MyClientCallback : public BLEClientCallbacks {
 void onConnect(BLEClient* pclient) {
 }
 void onDisconnect(BLEClient* pclient) {
 connected = false;
 Serial.println("onDisconnect");
 }
};

But the code don't take any difference between both. which means, if the Client connect/disconnect, the server is "seen" as connected/disconnected too and start/stop its tasks.
in short onConnect() doesn't differentiate which server is targeted.
Is it "normal"? I was in the expectation that they would be both differently handled.