Is it permissible to add to the well-known Talbiyah in Hajj and 'Umrah?

The Talbiyah of the Prophet, peace and blessings be upon him, was: "Labbayka Allahumma Labbayk, Labbayk, La Shareeka Laka Labbayk. Innal-hamda wan-ni'mata Laka wal-mulk, La shareeka Lak" (Here I am, O Allah, here I am. Here I am, You have no partner, here I am. Indeed, all praise, grace, and sovereignty belong to You. You have no partner). It was also reported from him, peace and blessings be upon him, that he said: "Labbayka Ilaaha al-Haqq" (Here I am, O God of Truth). The Prophet, peace and blessings be upon him, also approved of the Companions adding to this formula, such as the addition of Ibn 'Umar: "Labbayka Labbayka wa Sa'dayk, wal-khayru bi-yadayk, Labbayka war-raghbaa'u ilayka wal-'amal" (Here I am, here I am, and at Your service. All good is in Your hands. Here I am, and all longing and action are directed to You), and the addition of 'Umar: "Labbayk marghooban aw marhooban, Labbayk Dhal-na'maa'i wal-fadl al-hasan" (Here I am, whether desired or feared. Here I am, O Possessor of blessings and excellent favor). Therefore, it is best for the pilgrim performing Hajj or 'Umrah to adhere to the Talbiyah of the Messenger, peace and blessings be upon him. However, if he adds words that have been reported from the Companions or others, it is permissible.