TBH, if you're not hearing any mains hum in your speakers when using the 3070 plus the adaptors, then there's not much to worry about.
But... apologies for the forthcoming tech nonsense... (I'll do my best to keep this simple, but no doubt someone will start debating this explanation)
For me, if I have a device that has a balanced XLR input, I'm always happier driving it with a balanced output, whether it's true-balanced or "quasi-balanced".
The number one most useful thing about balanced connections is that mains earth is not used as a reference for the audio signal. Balanced connections are also far more immune to interference than unbalanced, but for AV people, with our line-level signals and relatively short cable lengths, interference isn't a really concern.
A balanced input (nearly always on an XLR) has three connections, usually called "hot", "cold" and "ground". It measures the difference between the hot and cold connections, and that's what it uses as the audio signal.
The shield of the cable (pin one of the XLR) is connected to mains earth (usually). There's no signal on the shield, it purely helps prevent interference getting into the two signal wires. Because it's not used as part of the audio signal, you can disconnect it on one end of the XLR cable if you really need to... the cable will still be shielded, but now you're not connecting the mains earths of the preamp and the sub together via the XLR cable. Although, since mains earth isn't involved in transmitting the audio anyway, there's often no need to lift the earth at one end of the cable.
TL
R is - balanced connections almost never result in earth loop hum.
Unbalanced RCA connections can cause earth loops, and subwoofers are great candidates for this. (e.g. my REL Strata 3 <grr>). That's because, for everyone's safety, both the receiver and the sub are connected to mains earth via their power lead. But then the mains earths are connected together again via the shield of the RCA cable, because the RCA connector is usually mounted on an earthed bit of metal casework and/or connected to mains earth internally. This is a good recipe for earth loop hum, especially when both devices are plugged into different mains outlets, and you've got a long signal cable connecting them together as well.
As for different types of balanced output - in simple terms, "true balanced" outputs drive both the hot and cold pins with signal - the cold pin carries the same signal as the hot pin, but with the polarity flipped. A "quasi-balanced" output ties the cold pin to ground via a resistor, but the connection still works since the balanced input is measuring the difference between hot and cold pins, and signal - nothing = signal. It's no biggie which kind of balanced output you have. Mostly you don't know, and don't care.
I hope that made sense.
PS Beware of some older hi-fi equipment with XLR inputs that turn out NOT to be balanced inputs at all. That can be a head-scratcher.