Feature Request: Enable MathJax for posts from specific instances

I was wondering, could we have an off-by-default option to allow MathJax rendering in posts from specific instances? For example, [Mathsodon.xyz](https://mathstodon.xyz/) renders maths in their posts such that it looks like this in their instance:
Meanwhile, in Phanpy, it gets rendered as:

I feel like there could be a chance of false-negatives if this was activated for all posts, so I thought that there could be an list of allowed instances that could be user editable. It's okay if this feature gets decided as too complex, I understand it would only matter for a small number of users 😅