Arduino UNO WiFi: RestClient and RestServer

Juraj:
only /arduino/ is fixed. it is a factory and esp-link firmware feature.

about why is it slow and a path to full speed, I write in Uno WiFi & WiFi Link unofficial documentation

I read through the documentation. And, from what I understand, I have to install a new firmware to my UNO WiFi Developer Edition boards? Also, among the example sketches, it seems that only the WiFiRestServer.ino is posted. How about WiFiRestClient.ino?

Also, do I have to be forced to use the WiFi Link library over the UnoWifiDevEd library in terms of speed?

Thank you!