How to completely remove OpenCoreLegacyPatcher？As if it had never been installed！

I have an iMac 2015 27-inch 5K, which supports up to MacOS 12. But I need to use Xcode 15.3, which requires MacOS 14+. So I had to find a solution.

I found OpenCoreLegacyPatcher which can break through the restrictions and install the unsupported system. I was very excited and immediately followed the official tutorial and successfully installed the latest system MacOS14.5.

But what happened next was frustrating. I didn't feel any discomfort when using MacOS12.7.4, although I knew that the 1.0T hybrid hard drive had a slow read and write speed. But to be honest, I felt that everything was fine on macOS12.7.4.

However, after installing macOS14.5, it was really slow. It was completely unusable. I guarantee that I have installed the driver and patch correctly according to the official tutorial.

So, I had to restart and common+r to enter recovery mode, completely erase the internal disk and reinstall macOS12.

But something happened that puzzled me. Even though I had completely formatted the entire hard drive and reinstalled the system. But every time I started it, the screen would keep printing logs. This log should be the log of OpenCoreLegacyPatcher. I don't seem to have completely gotten rid of it.

So, how can I completely delete it, as if it had never been installed?

Supplement:

After reinstalling the system, I mounted EFI, but there were no OC-related files in it.