Aux is not the same as Coax. The Coax beside being 75ohms, the cables itself have to be constructed specifically
No it's not, coax has 75ohm impedance. Here is what you need. Choose 3pole option https://penonaudio.com/3.5mm-coaxial-cable-for-chord-mojo-dap.html
That is a theoretical requirement, especially for long cables, that the high frequency digital signal can be safely transmitted over cable lengths of several meters. If you have a well shielded and/or a short RCA cable (or a 3.5mm terminated interconnect cable) it will work as good.
And iBasso cable itself is 2-pole, but 3-pole cable will work as well.
"Assuming your S/PDIF cable has a velocity factor of .7 or higher, one wavelength at 6 MHz is at least 115 feet or 35 meters. If your S/PDIF cable is shorter than one-tenth of that, it is too short to function as a transmission line, so its characteristic impedance is irrelevant."