Open Rust-related systems research problems suitable for PhD?

TL;DR I'm currently trying to find a suitable topic for my PhD in the systems research field, any suggestions would be great, having it be Rust related would be fantastic.

So far I've been coming up short with ideas that are too small, more of an engineering problem than a research problem or otherwise unsuitable. I've been reading papers in recent conferences (UK Systems, HotOS, etc) but have yet to find the right open problem in need of further research.

I'm interested in operating systems (currently writing a Rust unikernel for my dissertation), filesystems, high performance computing, new networking/storage technologies (such as ZNS SSDs and related filesystem/OS work), but slightly less interested in the language theory/formal verification side of things.

Apologies if this is too close to asking for help with my homework, I thought at the very least it would make for some interesting discussion.