Is individually sending blessings upon the Prophet, peace and blessings be upon him, at one specific time, an innovation?

What was mentioned in the post is correct and acceptable. This act is not an innovation (bid'ah); rather, it is cooperation in righteousness and piety, enjoining good, and guiding to good. It is a good method, and there is no impediment to it, for it involves inventing a means that helps people remember to send prayers and peace upon the Messenger of Allah, may Allah bless him and grant him peace.