Is it considered an innovation (bid'ah) to send blessings and peace upon the Prophet or to seek forgiveness using formulas not mentioned in the Sunnah, or at specific times like before prayer?

Seeking forgiveness (Istighfar) and sending blessings upon the Prophet, peace and blessings be upon him, using the wordings mentioned in the Sunnah are superior and yield greater reward and blessing. It is permissible to use other wordings so long as they do not involve exaggeration or forbidden descriptions. It is recommended to do both frequently at all times, but singling out a specific time that has not been mentioned in the Shariah might lead to innovation (bid'ah).