Digital coaxial advice needed

I’m a revived audio nerd so i seek some advice.
I’m looking for inputs for 2 PC’s and one coaxial cable between Nurpime Evo dac and CDT-8 Pro transport.
All advices are appreciated.

It’s not HDMI, it’s the "I2S protocol" See this:²S

And here is Paul owner of PS Audio explaining it:
Yes i noted. As some say, google is your friend.
So, IS2 hammer both coaxial and aes/ebu balanced digital connection it seems!?
If so i don't get why there's only one port for IS2 on the dac i ordered.
If jitter is zero and bandwidth is top, you'd like to connect a streamer and a transport to IS2. Nobody is pulling cables back and forth so this is annoying. Now it seems balanced digital is better than coaxial, so best would probably be to use a transport using IS2 for a streamer and a balanced digital for transport, or am i making the wrong assumption?
I2S is not widely adopted yet. Mostly found on higher end equipment where maximum performance is the goal. My "Wyred 4 Sound" DAC also only has one I2S input. But my transport does not use it. That's not to say that SPDIF coax sounds bad, it does not. It's just not the best that is possible.
I use Mogami 2964 / Canare RCA coaxial from enoaudio bought at Amazon for ~$40. Running between Node2i and RME ADI-2 DAC. I have run RME bit test between these components on both the coaxial and another Toslink and the transmission is 100% correct. Even if you spent $40,000 on a super-exotic cable you wouldn't beat the 100% correctness result. Which tells me I could have gotten an even cheaper cable on B&H (Hosa?)
I just found 2 digital aes/ebu sets i used back in 2002.
One brand i don't remember, the other one is signal cable.
I also found 2 custom made Krell cast cables.

Perhaps i should try and see how these two digital cables work first.
If i don't hear much difference, i probably should skip my urge for better (more expensive) ditos. However, i am curious of Inakustiks 2404

I contacted the reseller of the Nuprime combo, he actually suggested to move up from CDT-8 Pro to CDT 10 instead of more "exotic cables".

Btw, how does Nordost Heimdall 2 sound?
Are they thin in lower mid and bass?

I remember the older Nordost were good match for bass heavy systems