Multiple Layered Bone Blend Caching?

I’m looking for a way to use multiple bone blends while caching an animation state.

Let me explain:

I have a torch item that can be held in my character’s left hand. The character is already using upper body and full body slots for blending things like attacking while running. But when I added a third slot for the left arm to hold a torch I ran into an issue where the torch arm goes back to the default full body pose after the attack animation is played (or any animation for that matter.) I’m using a montage for the torch animation, which might be one of the issues.

So I’m looking for a way to build my anim graph that allows me to cache the left arm animation state along with the full body, but I have no idea how to do so. Unfortunately I’d just followed a tutorial on blending the upper/full body slots so I’m not super well-versed on the anim blueprint in general. But I’m assuming I need to cache the left arm’s pose in order to return to it after an attack.

Any help would be appreciate.