The initial reason for buying an Orange Pi PC was to remotely used it as a server for the SDR dongle and run the rtl_tcp program. In my desktop PC, running Arch Linux and using Gqrx, I can connect remotely and avoid the massive interferences produced by my desktop.
Direct connection through ethernet cabling and 1GB switch showed that the Orange PI PC + RTL SDR + rtl_sdr, after some tweaking, would work just fine, with no annoying lag between commands and response to/from the rtl_tcp program when using the Gqrx.
The issue is/was that the location for my remote SDR would mean that the connection would be made through PLC: Power Line communications. PLC uses the power lines distributing electricity around the house as the medium to connect devices without using ethernet cables or wifi.
I had doubts that with my Devolo 200MBps PLC that would provide stable connectivity for the I/Q stream from rtl_tcp, but I was wrong. Using the rtl_tcp through the 200MBps PLC works like a charm, and I only have a slight lag (around 1s) between commands and response.
The problem with PLC is that them by themselves are also huge interference generators, and so I still have some noise issues, but nothing compared to the rtl sdr being near my computer. The 868Mhz ISM band is now pretty much clear and we can see all the devices communicating.