Could be perfect, if …

Unfortunately due to known (and still not resolved) issue described here https://wordpress.org/support/topic/fee-not-disappear-after-change-shipping/ cannot give more than 3 stars until it will be resolved. Have the same issue as described in the topic, which makes for me the plugin unusable unfortunately.