Removing the finger poses from the sitting/laying positions

[fluffy-critter]

When I add the sitting/laying animations to my avatar, the finger positions go extremely wonky because there's additive animations on the fingers. Is there a recommended way to disable this functionality, such as through an animation mask? I'm fairly new to this aspect of Unity so I'm not sure what the best way is to override the hand animations, aside from simply deleting those curves from the individual animations (which is a tedious and possibly error-prone process).

I'm using a headset whose controllers only do gesture hand motions rather than precise finger tracking, if that makes a difference.