DeviceOrientation controls Lock view to Model and only use Subtle movement ? (like facebook 3d photo)

Questions
1

I know device DeviceOrientation example has been removed due to inconsistent behavior across devices but ii think this usecase can still work without issues .

Camera is fixed and only small movement is used to tilt the camera ,like this video

i made a pivotGroup at the 0,0,0 and put the camera at 0,0,5 and added it as child of the pivotgroup
then output of the deviceOrientation controls(quaternion) is copied to the group

it works nicely ,but the model loads behind me or some other direction most of the time .

i tried adding dynamically adding alpha offset so that the model comes to the center , but pivotGroup.rotation.y = 0 is applicable for both front and back orientation so camera ends up looking behind the intended direction

anyone know how to lock on the model and just use subtle movement for tilting ?

  const alpha = device.alpha + offset.y

        const beta = device.beta + offset.x

        const gamma = device.gamma

        const orient = scope.screenOrientation

        if (alpha && beta && gamma) {

            gyroEuler.set(beta, alpha, gamma)


            _euler.set(
                THREE.MathUtils.degToRad(beta),
                THREE.MathUtils.degToRad(alpha),
                - THREE.MathUtils.degToRad(gamma),
                "YXZ") // 'ZXY' for the device, but 'YXZ' for us
            rawOutputQuaternion.setFromEuler(_euler) // orient the device
            rawOutputQuaternion.multiply(_q1) // camera looks out the back of the device, not the top
            rawOutputQuaternion.multiply(_q0.setFromAxisAngle(_zee, -THREE.MathUtils.degToRad(orient))) // adjust for screen orientation


            pivotGroup.quaternion.copy(rawOutputQuaternion)