The recipe "Boosted Wand (+1) Intelligence" does not work.
And "automatic ballista" (which in the recipe is called "Upgraded Mysterious Item") is useless - because I installed it before the fight, the fight started. And it doesn't shoot itself (which I expected from the description)! Its activation costs all 6 APs (I have a 6 AP mod, in vanilla it would cost 4 APs), - comes the shot at 80-90 damage, only (I had level 13 characters).
With such characteristics, automatic ballista has no meaning, please make it (for example) really automatic shoot once in a turn (without spending AP).