Fidelity is the same through a monster cable or a coat hanger. I choose not to believe.That Reddit post headlines with "3.7 V, 25 Amps". That has to be a typo. That's a 100 Watt battery!
As for the gold, I suppose it wouldn't make a difference, but I still think drawing that much current to the heater so quickly must have presented conductivity issues (over the entire circuit, not just the battery contacts)...
Bellevue it or not, there are some people who can tell the difference between gold and copper contacts on speaker cable connections.
Copper is normally coated in nickel too, then gold (nanometers). Electron transfer still has to travel through oxygen free copper or a bare metal capacitor. (Silver if you're serious, and why not with a $10k set up or the likes).
I own gold plated cables because I like their braided look and they have good shielding (this is what you want) and don't mind spending a bit for the sake of aesthetics.
But it really is for specific resilience to corrosion.
That's funny with the battery, I found the pic and linked the attached thread to explain what it was.
I think the added resistance from a dirty contact is causing heat build up.
There's also the hard to clean contact on the PCB which might have a bad effect on the overall circuit.