Pendant of the Violet Eye

I couldn't find any source literature that had decent theorycraft regarding Pendant of the Violet Eye. Before getting it a couple of weeks ago and before testing out a key mechanic which no-one has bothered to figure out, it was easily the best trinket available. Here's a brief description:

Let's assume you get 2 casts for each 5 second bloc you get (this includes all spells that cost mana, except I realized Judgement doesn't proc it probably because it doesn't trigger a gcd) This will mean that you will get (2+4+6+8) * 21mp5, totalling 420 mana. 420 mana every 2 minutes equates to 420/24=17.5mp5, which is very good considering 40int implies that:

40 * 1.1 (divine intellect) * 1.1 (bok) = 48.4 int * 15 => 726 mana.
48.4 int * 0.35 (holy guidance) => ~17 healing.
48.4 int / 80 (int:crit) * 22.07 (rating:crit) = ~13 crit rating.

726 mana for a 10 minute fight is => 726 / (600) * 5 = ~6mp5 (12mp5 for 5min)

It's generally the best for the majority of fights imo. Unfortunately as I've tested out, you won't get the last mp5 proc due to the way the buff works...

When you use the trinket, the Trinket 20s expiry buff begins to count. After your first spell is cast, the 'Enlightenment' buff begins. The Enlightenment buff basically keeps track of how many casts have been casted, e.g Enlightenment (6). What happens is that the Enlightenment buff expires along with the expiry buff so it's not logically possible to get the last proc -_-'' This implies that it's only ideal to get 2+4+6 procs, which equates to 10.5mp5~