I've been decompiling and patching a wide range of software using codex with ida-pro-mcp and radare2 for generic targets, various language-specific tools for .net and java for example. IDA is heavily scriptable so the LLM usually ends up interacting rather interesting ways, but generally extremely effectively.

I'm not paying for the tokens I use, so I just choose whatever is the most performant model OpenAI offers. I find LLMs to be highly capable, struggling very little even against fairly obnoxious obfuscation.

My use cases have ranged from malware analysis to adding new features to complicated EOL enterprise software without access to the source code.

I've done a lot of manual reverse engineering. In many cases you can genuinely 100x your productivity using these tools. Tasks like matching decompilation are an especially good fit for LLMs.