yii2-pace/src/Pace.php
$this->getView()->registerJs('window.paceOptions=' . Json::encode(ArrayHelper::getValue($paceOptions,'options')), \yii\web\View::POS_BEGIN);
yii2-pace/src/PaceAsset.php
'position' => \yii\web\View::POS_HEAD
You place pace-js library in head and window.paceOptions={...} after that in body, so it isn't used.
Am I right?