I've replaced the rather loud ML Pros with 4 Noctua NF-A20. Amazing fans. Can't hear them at all on the rad.
Thanks to the Aquacomputer OCTO - The little brother of their more famous Aquaero - I now have access to 8 independent fan headers, 4 temperature headers, 1 flow sensor header, and 2 more ARGB headers. This also allows me to remove one fan splitter, and only run two cables to the radiator - SATA power for the pump and one RPM from the OCTO. It's possible to run the fans off the integrated fan header on the pump, but since I don't have it hooked up to anything else, there is no software control and that would require me to run two cables anyways.

It's quite shocking what a 40 EUR device is capable of. We have motherboards that are beyond 1000 EUR but their fan management software is a complete joke compared to Aquasuite. I can not recommend OCTO and QUADRO PCBs enough. They're amazing and will be an important foundation for every future build.

This should be the last PC upgrade until I make the switch to a DDR5 platform and probably completely rebuild everything.

5900X is ordered and I am waiting patiently. For the upcoming CPU and GPU upgrade I have switched from X370 to a X570 Unify to make use of PCIe 4.0. The new 2 TB M.2 drive reduces cable clutter significantly, as I am now down 5 SATA cables and 2 daisy chained power cables that are no longer required to power storage. It's also incredibly fast. A new water filter will keep the blocks clean and is stuffed away in the rats nest of cables under the desk where the QDCs connect the case to the radiator which was also recently upgraded to use Noctua fans.