The Eliyahu Rabba (Siman 682 Ois 2) and the Mamar Mordechai (Siman 682 Ois 3) both write that if someone forgets to say Al HaNissim in Shemoneh Esrei and are holding by the end in Elokei Notzer then they may add their the "HaRachaman" nusach that we say in Bircas HaMazon if one forgets to say Al HaNissim. The Eliyahu Rabba writes the Taz also says this.

What other achronim discussed this question? Whether it be in favor of saying it or not? What I find interesting is that the Mishnah Brurah doesn't mention this at all, not in Siman 682 in Hilchos Channukah and not anywhere in Hilchos Purim where it would also be relevant (at least not from what I saw.)

The Eliyahu Rabba (Siman 682 Ois 2) and the Mamar Mordechai (Siman 682 Ois 3) both write that if someone forgets to say Al HaNissim in Shemoneh Esrei and are holding by the end in Elokei Notzer then they may add there the "HaRachaman" nusach that we say in Bircas HaMazon if one forgets to say Al HaNissim. The Eliyahu Rabba writes that the Taz also says this.

What other achronim discussed this question? Whether it be in favor of saying it or not? I did not see it mentioned in the Mishnah Brurah at all, not in Siman 682 in Hilchos Channukah where I would have expected it, and not anywhere in Hilchos Purim where it would also be relevant.