This is honestly one of the silliest things I hear and it upsets me every year. People see this in a Sefer and they start asking/researching what they are allowed to do and not. It’s a Minhag!! If it’s not your Minhag, then no research needs to be done. You just don’t avoid any Melachah because you were not one of the ones who was Noheg that way. It’s that simple. I get Shailos every year from girls/women asking what they’re allowed to do or not. The fact that you’re asking means that you weren’t Noheg it which means that you are allowed to do any Melachah.
Old man: Yes, I have met two families who are Noheg to actually treat it like Shabbos, Melachos Ochel Nefesh included.