Is an 'umrah accepted from someone who assumes ihram from the miqat and dedicates the reward of this 'umrah to Muslims, and do they receive the reward?

Donating the reward of good deeds to a living or deceased Muslim is a matter of scholarly disagreement. The preponderant view is that nothing reaches the deceased except what the texts indicate reaches them, such as charity and supplication; this is based on the Almighty's saying: "And that there is not for man except that for which he strives." Donating the reward of good deeds to all Muslims in general is not legislated, nor has it been authentically reported from the Salaf. Sheikh al-Islam Ibn Taymiyyah was asked about donating the reward of reciting the Qur'an to the Messenger of Allah or to all the people of the earth. He replied that it has not reached us that any of the Salaf did so, and that the earliest to do it was Ali ibn al-Muwaffaq, and that emulating the Companions and the Tabi'un is more appropriate. Therefore, the prescribed actions that a believer should strive for are sending blessings upon the Prophet, supplicating for believing men and women, and seeking forgiveness for them. Hence, it is not legislated to donate the reward of Umrah to all Muslims, even if the intention is good. It is therefore necessary to restrict oneself to what the Messenger of Allah, peace and blessings be upon him, legislated.