What is the ruling on audibly invoking blessings upon the Prophet after the congregational obligatory prayer?

Reciting blessings upon the Prophet, peace and blessings be upon him, collectively and loudly after the prayers is a rejected innovation (bid'ah mardudah), based on the Prophet's, peace and blessings be upon him, saying: "Whoever introduces into this matter of ours that which is not from it, will have it rejected." This act was neither known to have been performed by the Companions nor the Tabi'in. Furthermore, it disturbs those who are catching up on prayers (al-musalli al-masbuq) and those who wish to adhere to the prescribed remembrances (adhkar masnunah).