Does the boot partition NEED to be mounted for every OS in a multiboot situation?

1. I’m running multiple EFI linux systems (emphasis on EFI) on a drive.
2. One (and only one) of them has rEFInd installed on it (I have a personal aversion to GRUB).
3. Every single one of them has the EFI partition mounted.

This configuration works just fine.

Now, if I remove the EFI system partition’s entry from the fstab of every system (other than the one that has rEFInd installed), everything should be working just fine.

Why am I wrong? Or if I am correct, what precautions should I be takng?

Note: One of the systems is actually GhostBSD, so feel free to extend your answer.