I don’t know, I never kept one. I believe there are some bootloaders that allow that. At least the restore sector is kept, and if you decide to roll back/sell,

I don’t know, I never kept one. I believe there are some bootloaders that allow that. At least the restore sector is kept, and if you decide to roll back/sell, you can restore macOS. Although I used it for years, and also having about 14 years of GNU/Linux experience, I was very comfortable.