Would it be more worth it to go 40/40 on Dex and Fth for miracles or should I just stick with Pure Dex?

Build - https://soulsplanner.com/darksouls3/184483

For context, this is my Pure Dex build that happened to turn into some kind of regen setup, but it has multiple builds in one, like a crit-fisher or a combo-heavy duelist using an offhand Estoc. I decided on Pure Dex simply because that seemed like the best choice, but now I'm wondering if it'd be more worth it to invest into Fth for lightning miracles and such. What do you think?

Tldr: Title