How is a competent Multiboot being made today in our UEFI era?

Question

GRUB

Please describe the general scheme of a multiboot system without reference to specific conditions. I know several approaches - installing on different partitions using Refind and booting from a flash drive, or from an HDD with GRUB. Or even installing different operating systems on physically different drives with a constant boot selection from the UEFI menu. But all of them subjectively seem to be some kind of curves. Can there be 2 or more EFI-System partitions on one HDD? Is it possible to boot multiple systems from the same EFI-System partition? Is it possible to do without using GRUB if I use elilo+Reffind?
Most of all, the Win7 + linux bundle is of interest as the most relevant.
PS Google produces a lot of irrelevant garbage about BIOS and MBR. Despite the fact that some important UEFIs are not able to load a 16-bit bootloader with MBR at all, for example, some motherboards from Microstar. Therefore, we say to the BIOS together "Farewell!".

Answer 1

have you looked at the arch linux wiki? there is quite a lot of information there - an example ...
I myself use the syslinux bootloader, so I will not advise much.
https://wiki.archlinux.org/index.php/Gummiboot