PW4 Kindle Firmware 5.10.2 PW4 Downgrade

Hello everybody. Yesterday I got the new PW4. I turned it on, connected to WiFi and linked it with my Amazon account. From the box I had 5.10.0.2 frimware. And it updated automatically to 5.10.2. Now from what I read, I can't do JB on this frimware version and I would like to know if it possible to downgrade on 5.10.0.2 or previous frimware versions.

Thanks in advance.