How long for an HDMI cable to break in.

If you are using the HDMI cable to transmit native HDMI I would not expect to ever detect any difference.  That is provided the cable is rated at high enough speed and the devices at each end support what you want to do. If it works, it works.

On the other hand, if you are using it for I2S all bets are off ...

I am using it for I2S.

What should be the result?

And is putting the cable in the freezer is that a joke? In the audiophile world you can never be sure.

@goleksiak   🤣

Wow, love audio humour. Zillion dollar cables, thousand year break-in’s, cryogenic’s, not to mention pads, pastes, weights, risers…