Opera's "VPN", regardless of Developer edition browser or not, is a HTTPS proxy. As long as it's enabled, and resources are accessed using HTTP/S protocols, the network requests will go through the proxy. FTP protocol doesn't go through the proxy, because it's not compatible with HTTP/S proxy. The only exception are network requests to servers for browser update and browser services, which bypass the proxy.

Hi, I´m a pretty Proxy/VPN noob, I could read earlier that, if you are using a proxy server with a standard browser, the http(s)-part is running over the proxy-server while with downloads your org. IP is visible. Now I wonder if downloads via Opera Developer are also get processed over it´s VPN? Thank you.

downloads via Opera Developer VPN?