Is the addition to the the wording of the Tasleem by saying, "wa barakatuh" (and His blessings) restricted to the Imam, or is it permissible for the one being led in prayer to say it even if the Imam does not say it?

Scholars have differed regarding the desirability of adding "wa barakatuhu" (and His blessings) to the salaam. It has been reported from the jurists of the Hanbali and Shafi'i schools that it is not desirable, while others have deemed it desirable. The source of this difference lies in their disagreement over the authentication of the narrations that include this addition. The matter is broad. There is no harm for the congregant (ma'mum) in performing the salaam with a wording different from that of his imam, as the required following mentioned in the Prophet's (peace be upon him) saying: "Indeed, the Imam was appointed to be followed," pertains specifically to the Imam's outward actions, and not to all of his states.