Also, if you’re using EFI, you can use something like efibootmgr to select which entry to use on next boot up. Handy if you want to swap between OS installs without breaking out a remote KVM or hassle with GRUB monitoring all your drives.

efibootmgr(8): change EFI Boot Manager - Linux man page https://linux.die.net/man/8/efibootmgr