1. I know it is slightly off topic but it was mentioned. I don’t see how tucking in one’s shirt would negate the shitah of the Admor Hazaken in Shulchan Aruch Harav. Unless I misremember and misunderstand, the Admor Hazaken holds that if the beged becomes folded over it is problematic, and therefore you need to be careful that on both sides it is spread out atleast one amah to be yotzei. If you wear a bendel to hold down the beged (as many lubavitchers do) you can then pull the strings up and over the waist of the pants without folding the beged.
2. In Russia chassidim in the country didn’t even wear shirts. They wore an undershirt and a tallis katon and a rekel over that. Shirts started to become a thing in the cities and in places where Western culture reigned supreme. Who says that a shirt needs to be tucked in???? I tuck my shirt in when I have to go to a work related meeting but honestly who cares and why do they care? Fashion is a klipa and it is best to not fall in line.
3. On a related note and true to the thread topic: I wear a hat because The Rebbe wants me to. Every once in awhile I buy a new hat and it for the most part looks like any old Borsalino (with the exception being that I do not like the large brims and crowns which have become the norm in some places). However, I wear my hat in the rain, and I wear my hat at the seudos, and I wear my hat when I am shvitzing, and I rolled on the floor at hakafos, and a hundred other things and hats get worn out. If you look at pictures from the early 1900’s you will see the average hat looks worn. It is a new thing that people are so particular and careful and treat a hat with such a level of respect that halevy they would treat a Jew with.