Sequencer Stencil Value

Is it possible to record and manipulate the stencil value of a mesh? EG. I have a skeletal mesh for a player that changes (during gameplay) the stencil value. With some stencil values the post processing renders the player visible through walls, and at other times it doesn’t.

By default with my setup it appears the stencil value is NOT recorded into sequencer, and I can’t seem to add a track for it. Maybe this is just a feature request, or maybe I’m missing a way to add custom parameters?