My experience is limited to the Dragon Age games and a few RPG books (namely, a 2015 Core Rulebook, Players' and GM's Guide v1.2) and I've played Inquisition as an attempt to prime myself to write an adventure in the setting.
I want a Tevinter Mage to assault a Qunari-held Fortress with the aid of magic shell-loaded gunpowder cannons. In essence, it'd be Magical Spellslinging, except mortar-sized... with a potential endgame being a rush to prevent the development and application of Artillery-sized weapons. ... Possibly, "Big Bertha" level arms' race escalation.
My question is this: I've seen that Rebel Mages in Inquisition would carry spellbooks upon which they had trapped spirits of the Fade and commanded them. Could spirits be bound to a cannon? Or to the shells themselves? What sort of repercussion would the developer of such devices have to contend with? Would the Chantry put a Holy Crusade against him/her/it? Would Tevinter back, either officially or unofficially, such an idea? And would the Qunari, in particular, employ methods to cease such research, due to their innate distrust of all things magical?