So, ujm, you’re saying that it’s ok to follow the MB in an area that conforms with your narrow view, but if it doesn’t fit, then the MB goes out the window?
The point is that the MB says you should dress according to the minhag hamakom. That doesn’t mean that in Brazil, since people don’t dress nicely, you don’t have to. People there do dress nicely for appropriate occasions, and that is how you should dress for davening. If that means pressed pants and a button-down shirt, so be it!