I remember a brother (not elder/MS) who got one and the elders got all upset with him, that he could not have one. He kept it though.
I was in a congregation that forbid them to be put in the aisle after 3 older people tripped over them on the way to the restroom.
In Jesus' time the religious leaders competed as to who had the largest of these.
Insight book
Jesus Christ condemned the hypocrisy of the scribes and Pharisees, who, in order to impress others with their righteousness, broadened the scripture-containing cases that they wore as safeguards. (Mt 23:2, 5) The Greek word phy·la·kte′ri·on, “phylactery,” which applies to such a scripture-containing case, means primarily an outpost, fortification, or safeguard. These were worn, therefore, as a safeguard, amulet, or charm.