Using a custom preamble

[Arad Arbel]

I'm able to render tikz-cd diagrams alright, and separately I'm able to use the Extended MathJax obsidian plugin to use commands from a custom preamble in inline equations. I'd like to be able to use custom commands in diagrams (like on nodes and arrow labels and whatnot).
I tried adding \input{preamble.sty} at the top of the tikz block but it can't find the file, and I'm not sure which relative directory is it going to search in. Is there a reliable way to make it work?

[Mayuran Visakan]

I'm not entirely sure how tikzjax works, I hope to look into it over the next few days, but one of the main things that would help this is if it uses a MathJax config under the hood. If that is the case, then the MathJax object could be loaded with the preamble as in the extended latex package. This would have to be inserted into the bundled script though which could be quite hard.