Maintaining Family Ties and the Specified Duration Thereof

Your Eminence! Are my maternal grandfather, my maternal uncle, and their sons considered relatives whom I must maintain ties with? And what is the recognized duration such that if a person exceeds it, he is considered to have severed his kinship ties?
You know that maintaining ties in the Qur'an and the Sunnah is absolute,Allah the Mighty and Majestic says: [Surah al-Ra'd: 21] ,And he says: [Surah Muhammad: 22] and the Prophet (peace and blessings be upon him) mentioned maintaining kinship ties in multiple hadiths without restricting it to a specific thing. Therefore, it reverts to custom. Custom varies among people according to their degree of kinship with the person, according to their need for maintaining ties, and according to people's circumstances. For example, people in a time of poverty may need a relative to be supported with financial maintenance—food, drink, clothing, and the like—more than if people were in a time of wealth.Similarly, for example: A sick relative needs more care than a relative who is not sick. So, what is customary as maintaining ties is maintaining ties, and what is customary as severing ties is severing ties. People today do not consider it obligatory to go to a relative every day, except for a very close relative like a mother or father. They do not consider it severing ties if one maintains ties with them once a month or on special occasions. The important thing is that this matter reverts to custom and usage.