ToME: the Tales of Maj'Eyal

I get the feeling from reading over some of the mage forum that I might not be using disruption shield effectively. For most shields, it is fine to layer them (if expecting fast damage) or use them one at a time. Disruption is an outlier since it has triggers for when it can happen, lacks a turn limit, and explodes regardless of damage taken if you're at full mana. I do trigger it if its an option in battle, but since I rest between battles, it's basically very likely to pop at the start of the next one if I don't turn it off.

How do the experts use it?

I may not be an expert, but I used it in one of three cases:
-Fighting an antimagic fighter (Zigur patrols, Kra'tor)
-I just spammed high mana cost spells, so I switch it on
-long boss fights