Is it permissible to say "Sayyiduna" (our master) before the names "Muhammad" and "Ibrahim" in the Ibrahimiyya prayer, or is it sufficient to say "Muhammad, peace be upon him, and Ibrahim, peace be upon him"?

The fixed wording of the Ibrahimiyya Prayer in the Two Sahihs and other collections does not include the phrase "Sayyidina" (our master), neither before mentioning Muhammad (peace be upon him) nor before mentioning Ibrahim (peace be upon him). The proof for this is the hadith of Ka'b ibn Ujrah: "O Allah, send prayers upon Muhammad and upon the family of Muhammad, as You sent prayers upon Ibrahim and upon the family of Ibrahim. Verily, You are Praiseworthy and Glorious. O Allah, bless Muhammad and the family of Muhammad, as You blessed Ibrahim and the family of Ibrahim. Verily, You are Praiseworthy and Glorious." Al-Hafiz Ibn Hajar transmitted that the word "Sayyidina" is not authentically established in any of the formulas for sending prayers upon him (peace be upon him). Therefore, one should restrict oneself to the الفاظ المأثورة (transmitted wordings) found in the authentic Sunnah.