Is it obligatory to mention the full phrase "ṣallallāhu ʿalayhi wa-sallam" (may Allah bless him and grant him peace) every time the Prophet's name is mentioned, even if his name is repeated within the same context?

A Muslim is required to invoke blessings upon the Prophet, peace and blessings be upon him, whenever his name is mentioned. Some scholars have gone further to state that it is obligatory, citing the hadith: "May the nose of a man be rubbed in the dust, in whose presence I am mentioned and he does not invoke blessings upon me," and "The miser is he in whose presence I am mentioned and he does not invoke blessings upon me."