Perhaps you can use pandoc to turn Typst into Latex and then do the little dance of making it compatible with the provided headers?
[ The latter is painful no matter what; once, I had a paper that I simply could not get to compile with the journal's header and had to give it to a wizard for examination. He did some manual TeX shenanigans resulting in a big blob of raw TeX at the preamble and it all worked. ]
the pandoc typst reader is a bit barebones, it doesn’t support packages (understandable) and seems to get confused with functions for me…though it’s been a bit since i tried it
[ The latter is painful no matter what; once, I had a paper that I simply could not get to compile with the journal's header and had to give it to a wizard for examination. He did some manual TeX shenanigans resulting in a big blob of raw TeX at the preamble and it all worked. ]