What are the wrongdoings for which their perpetrators are to be boycotted? And what is the criterion?

Question:
The one who shaves his beard and displays disobedience: is the greeting of peace returned to him?

Answer:
This is an apparent wrong that merits boycott, but only after he has been advised and taught that this is not permissible, and that it is a wrong. Indeed, some people think there is nothing wrong with it because they have seen this practice become widespread among people, so it may be confusing for some. However, he must be taught, guided, and the truth made clear to him, because the widespread occurrence of this among people may cause confusion regarding the matter. We ask Allah for safety from it.
Q: Is boycott applied absolutely to everyone?
A: If there is a benefit in it. As for if the benefit requires not boycotting him for the sake of the Muslims' interest, it is not for the purpose of eating and drinking with him. No, rather, if it is for the Muslims' interest, there is no harm in not boycotting him; rather, he should be rebuked and the advice should be continued.
Q: What if the boycott does not deter him?
A: Even if it does not deter him, there is no good in sitting with him and eating with him. However, if not boycotting him is in the interest of the Muslims, a religious interest.
Ibn Abd al-Qawi (may Allah have mercy on him) says:
Boycotting the one who displays sins is a recommended practice
And it has been said that deterring him is more obligatory and more emphatic
And it has been said absolutely, as long as he is open about it
And meet him with a frowning, stern face
So there are three opinions in this matter: that boycott is a recommended practice absolutely, or that it is obligatory absolutely, or that it is detailed: if it deters, it is obligatory; if it does not deter, it is not obligatory.
Q: This is a widespread affliction. If every man who shaves his beard or disobeys is boycotted, most people would be boycotted?
A: In any case, it is obligatory for a person to focus on what is better. He should strive against his own self and do what is better, not for his desires, but for the Shari'ah interest. Otherwise, the affliction is undoubtedly great.
Q: Is guiding them one of the interests of the Muslims?
A: I mean: it is not for the sake of his love, or for the sake of kinship, or for such reasons, but for the Islamic interests, considering the Islamic interests.
Q: Do you mean intending to guide him and make him love the truth?
A: Yes, or to repel a wrong from him, or to repel harm from the Muslims, or similar matters.