Live Link Face for Unreal Engine Calibration

Unfortunately the Live Link Face for Unreal Engine App is missing the Calibration feature of the older one you had to compile yourself.
Is this going to be added in?

Turns out the calibration process at the beginning is crucial, unfortunately that’s not included in the current App but you have to manually adjust it in the blueprint.

Would be really cool to make the blueprint do it, shouldn’t be too hard. Just record the values of all blend shapes when your face is not moving and use them as offsets.…-unreal-engine

How do you go about recording the values of the face?

I am running into the same issue here. There are some tutorials out there how to go about this and tweak those values manually but there should be a way to just get a rest pose from the iPhone first and store it.
I tried to use the GetFaceBlendShapeAmount function Get Face Blend Shape Amount | Unreal Engine Documentation but that is only returning 0.0 all the time. Maybe I invoked it in the wrong Blueprint. Used the Pawn from the FaceARSample scene where I stripped out all the other logic before.
Just to be clear: the tracking works and the geo is updating. Just cannot get the blend shape values.