I've modded in the past a long time ago, but I'm not familiar with modern papyrus or SKSE's extensions.
Is there a way to get the real-time modified cost of a spell (i.e. its actual cost when cast by a player) when that spell is cast?
I'm thinking of making a mod that converts magicka cost to health cost, but rather than using fixed health costs (like Path of Sorcery does with its Blood Mage perk) I'm looking to scale it based on what the adjusted cost would be in magicka.
My thinking is if the cost can be grabbed on spell cast then an equivalent health value can be calculated and subtracted while the magicka value is refunded. This would maximise compatibility with other magic mods.
This would also pair nicely with a script effect to set maximum magicka to maximum health (with appropriate balancing adjustments), which would allow me to script a toggle for lethal casting on/off. My guess is that the way existing alternative casting mods handle this is by discounting magicka costs to zero, hence Path of Sorcery's fixed costs, and I'd like to avoid that if possible so that cost-adjusting enchantments can still be worthwhile.