Yes, the box trace is probably unavoidable.
The single line trace is cheap though.
Make sure to disable it with a conditional (bool).
And toggle the boolean back to on when the input key is pressed and you are in a wall cover state.
Keep in mind, if you shrink the box to fit between belly and butt you may not need the trace.
It then depends on the animation, as the animation can be ourside the capluse.
Thats really where predictive animation comes in…
Trace from:
The hands (palm down plam up),
The head (all 4 dir, plus up.),
spine, one backwards one forwards.
Pelvis, back, forward and down.
Knees, forward.
Heel, backwards down.
Toes, forward up/down.
Then you invent a way to adjust the animation so it doesnt clip situationally to the action.
Each trace is obviously toggled on/off and only used once when the action you want to fine-tune at runtime starts.