>>394903539
Write Defaults makes expression layers easier because you can just put the facial expressions in like with avatars 2.0 and it will automatically just reset your face for you
But of course this doesn't work so well when combined with the animator blend tree system that VRC uses to combine multiple controllers together, so it's best to no longer use it.
You can put a "reset face" animation on a layer above your facial expressions which will basically achieve the same effect with less bugs. The reset layer will run first and reset all your facial expressions, and all the shit below it can still then apply facial expressions without having to worry about un-setting those shapekeys.