What LLMs are (still?) not good at is one-shot reverse engineering for understanding by a non-expert. If that's your goal, don't blindly use an LLM. People already know that you getting an LLM to write prose or code is bad, but it's worth remembering that doing this for decompilation is even harder :)
I asked Opus how hard it would be to port the script extender for Baldurs Gate 3 from Windows to the native Linux Build. It outlined that it would be very difficult for someone without reverse engineering experience, and correctly pointed out they are using different compilers, so it's not a simple mapping exercise. It's recommendation was not to try unless I was a Ghrida master and had lots of time in my hands.
I've had CC build semi-complex Tauri, PyQT6, Rust and SvelteKit apps for me without me having ever touched that language. Is the code quality good? Probably not. But all those apps were local-only tools or had less than 10 users so it doesn't matter.
For this project, it described its reasoning well, and knowing my own skillset, and surface level info on how one would start this, it had many good points that made the project not realistic for me.