A major upgrade featuring a full platform change (Z87 to Z390), fresh custom cables, opaque coolant and above all, my first time using borosilicate glass tubing.
Challenging to say the least, this has been my favourite build to date and I cannot wait to replicate something similar in the future.
Note, I faced ventilation/cooling capacity issues in this case at this point, likely due to the sheer heat output of the 9900k, motherboard VRMs and RAM cooling.