The following response provides an indirect response to the original question and concludes with the relationship to Exodus 34:7 (i.e., the verse in question).
In the Leningrad Codex the Masoretes recognized only one enlarged nun in Scripture, which is found in the last letter of the word "משפטן" in Numbers 27:5. (The margin note of the Masoretic Text states "ל̇ נון רב̇," which means, "one occurrence of the enlarged nun.")
Please click the below image in order to view the source document online.

However, when we view the same passage from the Dead Sea Scrolls, there is no apparent large nun evident. In other words, the enlarged nun in the Masoretic Text appears to be a later editorial addition for special emphasis.
Please click the below image in order to view the source document online.

According to Yeivin (1980), there are three reasons for large letters in the Masoretic Text:
1) the letter stands at the beginning of a book or at the beginning of a new section;
2) the letter draws attention to a significant statistical point, e.g., the large letter in Lev. 11:42 marks the middle of the Torah in letters; and
3) the letter shows that the reading must be precise.
As in the case in Exodus 34:7 (where Midrash appears to have added the large nun) the sole appearance of the only enlarged nun in Numbers 27:5 may have been to provide unequivocal emphasis that the case which Moses brought before the Lord was on behalf of women. That is, the emphasis was that for the first time in the Torah, the rights and claims of women came before the Lord.
Reference:
Yeivin, Israel (1980). Introduction to the Tiberian Masorah. Trans. and Ed. E. J. Revell. "Masoretic Studies," No. 5. Missoula: Scholars Press, 47–48, #84.