Is a payment made to a woman in exchange for forgiving her pregnancy maintenance during Khul' valid?

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If a woman enters into Khul' (redemption divorce) without forgiving the maintenance for her pregnancy, she remains entitled to maintenance, similar to a triple divorce while pregnant, as the fetus is his child. If she forgives the pregnancy maintenance as part of the Khul' consideration, it is valid, whether it is the entire consideration or part of it. Such a release covers the duration for which the woman is entitled to compensation, which is the period of pregnancy and nursing (Rada'ah). If the duration of nursing is disputed, it defaults to two years, based on the verses concerning weaning: "And their weaning is in two years" (Quran 31:14) and "The mothers shall give suck to their offspring for two whole years, for those who wish to complete the suckling" (Quran 2:233). If they specify the period of release as the duration of pregnancy, one year, or similar, the stipulated period governs, which is considered better for preventing disputes.