Youngsters will not remember, but in the 70’s during the era of the Pet Rock, there was a thing called the Square Egg. It was like a tiny grape press on a tiny Lucite box, iirc, and you put a hard boiled egg into it.
I only bring this up because I sense a comeback.
I have one of those, purchased solely to impress and make a conversation piece in a dish for a party. Haven’t used it yet for a party yet, but it works! You have to put the boiled egg in while it’s still warm, and then chill it for awhile. Comes out square :-)