In my world "Balanced" is "Balanced" and that means 3 wires/connection. One for the + side off the signal, one for the - side and a separate one for the ground/shield. There is no such thing as a two wire balanced connection. In audio, especially pro audio, we have to shield both sides of a signal (-/+) from the effects of interference. If the shield or ground is being used for a part of the signal transfer, then half the signal is susceptible to interference, and therefore the whole purpose of "balanced" i.e. to provide a separate path to ground for interference, has been defeated. Two RCA cables will give you a separate shield wire for each channel, but those shields will be connected to a common electrical point in the device (Amp, or Headphones), hence no more separate ground. Electricity travels very, very fast and so doesn't care where the common connection happens.., could happen sooner, or later (amp or phones). Volume levels are a whole other thing and involve standards.
In pro audio, line level is +4db, or 14db higher than consumer line level, which is -10db. This difference helps create a better signal to noise ratio, much needed to handle the chores of recording and mixing several channels of audio down to stereo or multi-channel final product. This provides a better chance to keep the overall S/N ratio low through out the process. These conditions don't exist in consumer audio where only the final product is being experienced. I maintain that the claims of "balanced" in the devices you are interested in are mostly false, and more suited to creating sales. The final impedance of a device is due to the internal design circuitry and can be manipulated in any way a clever manufacturer wants to. Changing the wires do nothing to change this. The US Telephone service operated on a 600ohm balanced system, for decades, to enable better matching of external devices and facilitate patching calls from one area to another. This was referred to as 'impedance matching" and ran at that 600ohm value, which is considered high in the headphone world. When output impedance matches input impedance, transfer between devices is effortless as they cancel each other and enable calls to go across the country unimpeded, so to speak. Ok, this is too much talk.., sorry.