Yes nvapi is blocked because it's not supported for capture and replay. It can lead to corrupted captures due to missing commands/semantics, and might lead to crashes in some cases.
Can you explain what the actual crash is? RenderDoc blocking the nvapi_QueryInterface
call will just cause the function to return NVAPI_NO_IMPLEMENTATION
which needs to be handled by the calling code with a fallback path. In itself it's not a problem and shouldn't crash.