The best solution is the "not to run any controller software" solution.

So, tired of seeing my CPU usage and temps to oscillate up to 45c at idle and 5 to 10% constant CPU usage, and most importantly, coolant not going below 30c even in winter, I decided the best solution is to stop all of this extra software.

If Corsair is listening, RGB animations should be executed from the LNP/CP. Not from iCUE or the service. If the controllers can display a smooth rainbow demo I don't see why it couldn't display nice patterns injected by iCUE that operate entirely inside the controller without any CPU overhead. I can understand if there's a lack of memory to put something too complex or long but I can live with that.

As for system monitoring. I don't need to see my devices all the time, that's why I use HWInfo. Also is pointless to see your coolant temperatures at idle if iCUE is already using some CPU and heating up the coolant. I don't see an easy solution here other than an option to only monitor if iCUEs UI is open if the user so desires to minimize CPU usage.

If iCUE and the service were used solely to inject RGB animations into the controller and the service for the most part remains stopped then people could use HWmonitor without so much risk too.

That said, unless you guys have something under the sleeve to make the CPU usage near zero, but I doubt it. In the meantime I'm gonna be in rainbowland.

So for the record.

CPU temp was oscillating between 30 and 45c and after closing iCUE and the service the temp is 26c

With iCUE running, my coolant temp never goes below 30.

With iCUE and the service off and with an effective 0/1% idle CPU usage my coolant temp went down to 25c.

So, those 5c are the ones hurting the most, not so much the CPU usage itself.