Maybe I misunderstood you but last time I checked you can’t run switch functions from an Anim Graph. Also, I’ve recently had this same exact issue and I’ve found that it dates back at least 7 years so it’s a ridiculous issue that should have been resolved eons ago. I think it’s quite ridiculous that something as fundamental as hand placement has no proper procedural solutions. Two-Bone IK and Sockets is the closest thing aside from the fact that the way they are designed prohibits you from ever receiving the location at the proper time and so results in the hand always lagging one step behind the socket.
I mean honestly, it’s almost embarrassing to even mention this fact to people when they ask about this issue on almost a daily basis…To have to admit to people that the only proper solution is to tailor handmade animations specifically for hand placement if you want it too actually be accurate. When we have Ai out performing Artists on a daily basis and Nvidia showcasing Physic-Based Ai-Driven Animation systems.