I think that, along with any aspect of overclocking that is potentially dangerous, that as long as you pay attention to your own voltages, it can go either way. But for low Over clocks, why not leave it disabled?
But for the upper ones, or when the temp becomes a factor due to that high voltage you need just to have it droop down under load... It's time to enable LLC and get really soaring.
I can not prove or disprove that there comes more instability when it is enabled, because i don't have stability problems, ever, really. 😉
And my LLCs are usually always enabled, unless its an NVidia board!
Use HWMonitor, which records high, low and current voltages and junk, so if it spikes, all you need to do is look at HWMonitor, and it will have some odd 4.008 VCore listed right there if you had a spike!
--Lupi