What is the ruling on initiating the greeting of "peace" to Shiites when frequently interacting with them, given that they do not display their beliefs or engage in reviling?

How one deals with Shiites varies depending on the nature of their innovation (bid‘ah). If their innovation is considered fasiq (rendering one a transgressor) but does not take them out of Islam, such as their devotion to the Family of the Prophet (Ahl al-Bayt), then it is permissible to initiate the greeting of peace (salaam) with them, advise them, and even shun them if they persist in their innovation, provided that shunning achieves a benefit. However, shunning should be abandoned if not shunning is more beneficial. But if their innovation is considered makfir (rendering one a disbeliever), such as slandering the Companions or exaggerating the status of the Imams and invoking them, then it is not permissible to initiate the greeting of peace with them, nor to show them affection, nor to eat their ritually slaughtered meat. Rather, it is obligatory to despise them and disavow them until they believe in Allah alone. Similarly, it is generally not permissible to initiate a greeting with a disbeliever, but one should return their greeting in kind if they greet a Muslim.