>There's been some skepticism about whether they are truly high severity

To be honest this is an even bigger problem with Semgrep and other SAST tools. Developers just want the .1% of findings that actually lead to issues, but flagging patterns will always lead to huge false positive rates.

I do something similar as what you suggested and it does work well -pattern match + LLM. The downside is this only applies to SAST and so far nobody has found a way to address the findings that make up 90% of a security team's noise, namely SCA and container images.

My first use case of an LLM for security research was feeding Gemini Semgrep scan results of an open source repo. It definitely was a great way to get the LLM to start looking at something, and provide a usable sink + source flow for manual review.

I assumed I was still dealing with lots of false positives from Gemini due to using the free version and not being able to have it memorize the full code base. Either way combining those two tools makes the review process a lot more enjoyable.