V3: Change options by object(dict) after MathJax loaded

For version 2, we can change options by:

MathJax.Hub.Config(options);

which options is an object(dict):

options = {
  messageStyle: 'none',
};

But for version 3, seems I can only change options by dot:

MathJax.config.tex.inlineMath = ['$', '$'];

For some cases like I want to change some custom options without using statements rather than one line of code, version 2 options API is easy to be used more.