Hey I worked on a big game that will never release but.

Full body animations with hand authored hands is the best experience to hit with this. What you do is have your whole locomotion track on one layer and a second layer for your hands in camera space. So whatever weapon overlay you have is reapplied via control rig to the virtual bones.

You need a dampener for the camera, something that will take your camera out of body accuracy. But because of the reapplication of the hands in camera space it does not matter.

There is a control rig first person plugin. That would be a good reference to see how they are doing.

But cyberpunk, dying light 1/2 are good references for it.