Using `xz -9 -e` results in pretty reasonable compression, in comparison:

     19648  dommy-2.0.js
     28092  dommy-2.0.weird.js.xz
    115023  lodash-4.17.15.js
    138808  lodash-4.17.15.weird.js.xz
      7114  modernizr-custom.js
     11148  modernizr-custom.weird.js.xz