Is increasing the adhkar (remembrances) during rukoo’ (bowing), sujood (prostration), and rising from them, beyond the narrated adhkar, and to fill the remaining time before the imam moves, considered a correct action that should be continued and encouraged, or is it an innovation (bid’ah)?

We have previously mentioned the supplications for bowing (rukūʿ) and prostration (sujūd), the supplication after rising from bowing, and the supplication between the two prostrations. It is preferable to begin with the transmitted (ma'thūr) supplications, as they are comprehensive and sufficient, and one who occupies himself with them does not need anything else. For those who do not memorize all the transmitted supplications, there is no harm in reciting non-transmitted supplications or remembrances, without believing them to be sunnah (definition) in this specific position. It is incumbent upon the Muslim to learn the transmitted remembrances and teach them to others, for the authentic Sunnah is more worthy of being learned and conveyed, and it is sufficient above all else.