Some of the universal contractions require more symbols than the American ones do. As well, some contractions were eliminated entirely in UEB because they could cause ambiguity. Others had more strict rules instituted about when and how they could be used, to make those rules easier and avoid having rules with exceptions.

Please note, however, that I am extremely biased. The way I learned Braille (grade 2 American, and all Nemeth for math) when I was seven years old is, obviously, the way God intended Braille to be written, and probably how he wrote the ten commandments on those tablets he gave Moses back in the day. Modern changes to it are obviously abominations, and go against the natural order of things. Lucky for me, all of my devices still let me switch to Grade 2 American Braille anyway, so I can ignore this new fangled universal Braille code the kids want me to learn, and shake my cane angrily at them. Okay, Okay, I’m only 36. But that’s how I feel! LOL. If you want the pro-UEB argument, maybe one of the younger commenters who actually likes it can be provoked into an argument…uh…I mean debate. I think maybe @dhamlinmusic@dragonscave.space uses UEB?

As for signs, I have seen some with grade 2 Braille on them, especially when they have a lot of information to convey, like on a plaque with fire exit/emergency instructions for example, or in some museum exhibits with Braille information. But stuff like “bathroom”, button labels like open/on/off/start/stop, or elevator buttons, or room/class/office numbers, will generally be in grade 1, even when they could save a few symbols by using grade 2.