[2021] 15aps/180%ms/30%ActionSpeed Reverse Chill Raider - The Fastest CoC (video with and without poison sextant)

Something is unaccounted for, yes. I don't know what.

With exactly 110% increased effect of chill (or increased effect of chill on you, or any combination of those stats that totals 110%, because they're addiive), using Icefang Orbit, Winterweave, and The Golden Rule, when I hit and poison an enemy, my character gets a chilled, with a base magnitude of -10 (reversed from 10) and an effect modifiers of +110%, resulting in an action speed modifier of +21%, exactly as expected. Other values also give corect results. I cannot reproduce any other result in-game without something else that modifies the effect of the chill. Could be a modifier to ailment effect, elemental ailment effect, cold ailment effect, etc.

I can only conclude that the character either has some other modifiers to the effect of the chill applied to them than the 110% claimed in this thread, or has some other source of increased action speed (unlikely based on the screenshots, since it would presumably need to be also activated either by being chilled or by being poisoned).

EDIT: One of the other programmers has just found a bug introduced in 3.13 which causes some "increased effect of non-damaging ailments" modifiers to be applied twice - being correctly factored additivelty into the total increase modifier, and then applied again multiplicatively with that, instead of applying a different, multiplicative modifier stat. I didn't find this in my testing yesterday, but I believe it will be the source of the discrepancy seen here. This bug will be fixed, although I do not currently have an ETA on when that fix will be deployed.

Yes, that modifier is included as part of the multiplicative modifiers that was not being applied (because it was reapplying the additive one in it's place).