Spell Interruption Rate Down Equipment Cap

[Masamune]

Also i remember someone (Kaeko maybe ?) mentioning a theory saying -interrupt down would actually be a sorta "diminishing factor" on the casting time during which you would be interruptable, maybe starting from instant you cast.
Has it been debunked ? (thinking about something like, with -50% interrupt down, getting hit during 1st "phase" of spell casting = no interrupt, but getting hit during 2nd "phase" = interupted)

If that theory work, then PLD/nin could potentially mix shield skill, haste and fill remaining slots with spell interrupt down, to time their utsu casting exactly just before 1st hit (eat it) to allow spell get off just before next hit, with 100% success?

[Siniroth]

I understand what you're saying, but I have never heard the theory before... the closest I can think of is that some monster attack animations are long enough that the damage shows up in log after the attack processes, so if you start casting when the mob starts swinging, the attack happens in the middle of casting, but technically went through before you began casting so it doesn't have a chance to interrupt.

[Masamune]

a yes true i didnot think about lag ;;

i was thinking in terms of screen animations, not dmg on log.

I'm just asking if the following theories have been debunked :
- damage received need to be "capped" to not get interrupted @ a given equipped+merited interruptdown%
- interrupt down% = uninterruptable % of casting time.