Question STW Fan Controller 4 pin Molex

Jul 12, 2020
Hello, I have a question and I hope I can get a newbie friendly answer. Hope I'm posting in the right place. I have attached links to specific products/connectors I'm discussing for extra clarity. Thanks in advance for helping me get through this :)
At the moment I have a cupboard with 16 fans. These 16 fans are controlled by 4 STW fan controllers.

I power these 4 STW fan controllers with a spare PC power supply unit (PSU) I have. I bypassed the requirement for a motherboard to turn on the PSU (besides the point). Each fan controller is connected to the PSU using 4pin MOLEX connectors.

As you can imagine, having 16 fans on at all times is not great as it produces too much noise. Each fan controller cools a different set of devices for my theater equipment.
What I wanted to do was add 12V radio frequency (RF) relays. They would be set to self-locking.
I was looking at buying 4 of the following relay switches:

QUESTION 1) How would I get this to work? And which cables go where? (I have a rough idea, but I'm not sure if it would work and I don't want to blow anything up). Otherwise, what would be a better solution?

QUESTION 2) Does this STW fan controller use both the 5v and 12v from the molex connector? Or only the 12v? Would I require 2 relays per fan controller for both the 5v and 12v connections and turn both relays on simultaneously?

Hope one of you can help me with this, I've been driving myself mad trying to figure out how to control each fan controller separately without having to go into the cupboard. The cupboard holds a lot of AV equipment in it... a bit of a DIY project on a vintage looking cupboard with modern equipment in it :)

(I would control the RF Relays with a broadlink RM Pro+)