your gonna mess up alot of things by editing status bar to be thinner.
If you do it, the time will have to be changed to be smaller and fit, then it will have to be modded again so miui can change where it's location is. All this but for pretty much every notification you'll ever get. all the icons are going to have to be smaller than before, and it may not even fit on the status bar.
Just use a lower dpi, im on 200 and it looks really good.