Euclid, Sindome has the same things you are talking about, I'm not sure why you are saying that we have more or less features that require processing time than other MU*.
I'd also like to point out that Sindome has anywhere between 2-10 times the population of other games, and these things don't always scale linearly as you might expect with players. There is a certain amount of background tasks that eat a percentage of utilization at all times, regardless of population. I'm no expert in this codebase, so I can't speak to the backend side of things, but I can say that most days, if you are watching the CPU utilization of the server we're not simply sitting idle. It's possible to code things with low overhead, but any kind of state-based and time-based check like what you are proposing is going to take it's toll
I think it would really depend on how the code handles current SIC commands. If doing a CH or CT is demanding (I assume it is not), then it might be possible that what you propose could lower some load as there will not be a need to constantly spam the server checking for SIC during brownouts.
In any case, I'm speaking in generalities here, so please don't assume I have any idea I know what I'm talking about with regards to the tech stack. I think it's a neat idea and I've thought about it once or twice, but this kind of thing can have a performance impact, which is why I'd assumed it had not been implemented.