Running minifiers twice

I ran UglifyJS twice and got a small further reduction in size. I now set the 'passes' option of 'UglifyJS' to '3'. This further reduces the size of the JavaScript in my game by 0.5%. I do not get much reduction in size when I run the 'CSSO' minifier twice or run the HTML minifier at 'jsonformatter.org' twice. The 'terser' JavaScript minifier is much faster than 'UglifyJS' but produces slightly bigger results with the default options.