Ill preface my comment with saying: this might not be the best solution give the goal of your project to iteratively loop through and improve on the tests each round, and using deps would make that process longer/more complicated having to work potentially with another project.

.....however.....

mago, a static analyzer for php is written in rust and might be useful for gaining some "free" performance uplift: https://github.com/carthage-software/mago. iirc it splits out a far bit of its internals so they can be used by other projects (citation needed)