Hi ADALM-PLUTO Designer(s),
some advanced users may want to utilize the second RX channel and TX channel of the AD9363. They generally have no problem adding some coupling Cs, baluns and coaxes to a system, but "digging" to the pin between the BGA and the PCB is generally frowned upon.
So please expose one differential pair of the second RX and TX channel from the ICs pins with a nice solderable pad (with at least one via holding it to the FR4). You can connect it to its termination net via a zero ohm resistor.
If you are feeling extra generous and have some real estate left, you could also provide some non populated footprints for decoupling Cs, baluns and micro coax soldering pads. But thats low priority.
Anyway, I think this is a really cool project, especially at that price.