来源：https://www.reddit.com/r/pathofexile/comments/7otuqi/designing_the_elder_uniques/dscukvn/
A small correction - the modifier with the same wording is on the Heirophant ascendancy, not Guardian (on the Sanctuary of Thought notable). It's also worded the same as all other "gain X as extra Y" modifiers, such as from Hatred or the Added Fire Damage support gem (and should thus work the same way).
It is also not correct to claim the ES granted by Sactuary of Thought is not affected by modifiers to ES - it is modified by them, and they apply as well as and and stack correctly with mana modifiers, in exactly the same was as both physical and cold damage "increased" modifiers will apply and stack additively to extra cold damage from Hatred.
There is also no difference between "base" and "non-base" ES*. What is happening is that the initial version of this stat was implemented incorrectly, making additive modifiers stack (sort of) multiplicatively, and in some cases potentially apply twice. The implementation should have been based on the existing stat used on Sanctuary of Thought, but was mistakenly actually based on a different stat with a similar-seeming internal, which is used internally as a base stat on some monsters to give them ES based on their total life. That stat (and the weird mechanics it uses) are not intended to go on players (but are safe on monsters simply because they don't get the same number of kinds of modifiers as players).
I spent some time yesterday being frantically confused as to why so many people were reporting this when I could see the code was clearly correct, but it turns out that's because Rian already fixed the code while I was away. I cannot at this time give any estimation as to when that bug fix will be patched to the live realm.
*At least with regard to any existing modifiers. There is, for example, a distinction between base and added Damage, which matters for "Effectiveness of Added Damage" on gems and a few other mechanics, but not currently for anything else.
将而言之，就是这个珠宝的es进行了两次加成
另外GGG其实早就注意到了这一点，并且由Rian修复了它，只是负责人不在，因此还没有上线。