option for refreshing preview always, or refresh button&shortcut in preview mode

I'm using mathjax for LaTeX math rendering support by using custom template.
$\int _a ^b f(x)dx$  > beautifully rendered form of integral from a to b f(x)dx
here is my template headerscript code.
<script type="text/javascript" async src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.2/MathJax.js"> MathJax.Hub.Config({ extensions: ["tex2jax.js", "TeX/AMSmath.js", "TeX/AMSsymbols.js"], jax: ["input/TeX", "output/HTMLCSS"], tex2jax: { inlineMath: [["$", "$"], ["\\(", "\\)"]], displayMath: [["$", "$"], ["\\[", "\\]"]] =}, "HTMLCSS": { availableFonts: ["TeX"], preferredFont: "TeX"}, "showProcessingMessages": false, "messageStyle": "none" }); </script>
In the first preview, It works great.
But when I add some math equation and preview, the added equation is not rendered.
So I have to reselect my custom template. Then Editorial reload my document, so problem is solved.However, I have to tap template  myCustomTemplate every single time when I want to show my document.
So I suggest new option, "always refresh preview." (default should be off.)and It would be helpful to add refresh button and keyboard shortcut(CMD+R) in preview mode.
then whether the option is on or off, users can refresh preview contents if needed.