Thanks for the information, Chewitt. With it, I was able to install LibreELEC on another hard drive, copy the partitions to the desired drive, and then create a new NVRAM entry using efibootmgr.
I respect your opinion, although the risk of installing LibreELEC on the wrong drive also exists with your method. I believe that having LibreELEC on a partition of a hard drive with other operating systems makes it more efficient and independent, and I hope you will consider this option in the future.
Regards.