The crown sits next to the head, while the necklace sits next to the heart. The New Church being the crown of Christendom merely means that the best understanding of Revelation and the Other World is found within the New Church. Those of us who have come to the Heavenly Doctrines from outside will testify to that.
However, the New Church is not necessarily better and excelling in love compared to other Christian churches. As long as we do not expand the meaning of "crown" to signify that we are inherently better and less prone to evil than other Christians, it is still OK to affirm that we have a clearer and brighter light (understanding/head) than the rest of Christendom (and no thanks to us for that!).