Shifter's Defensive Instinct + Sidestep Secret

[Verecoth]

So I'm trying to construct a Kobold Dragonblood Shifter and I'd settled on a one level dip into a Lore Oracle for Sidestep Secret, but now I'm looking at Defensive Instinct on the Shifter and wondering if they'd stack.

The Sidestep Secret revelation says that you use your Charisma mod in place of your Dexterity mod for AC and Reflex saves.

Defensive Instinct says you add your Wisdom mod, though my DM is letting me take a feat from the Legendary Shifters 3rd party book that shifts all Shifter features that depend on Wisdom to being based on Charisma. That said, it just says you add your modifier for that stat (if any) to your AC and CMD.

Would these two abilities stack? Would I get my Charisma as my Dex replacement and then get my Charisma again?

[Firebug]

Doesn't matter if its a replacement or not if its untyped. They don't stack due to the FAQ since the 'type' of the source is 'Charisma' bonus.

[blahpers]

Relevent erratum "FAQ"

TL;DR: Due to Cirque du Soleil levels of contortion by the rules design team, you can never apply two separate instances of the same untyped ability score bonus on the same roll.

Edit: Clarified "untyped", as you can still add an untyped ability score bonus to a typed ability score bonus even if they're the same ability score.

[Dragon78]

Verecoth, what is the name of that feat?