/boot/efi doesn’t make much sense for systemd-boot. That is the common mountpoint for grub.
Calamares has a fixed mountpoint for the EFI partition. We use /boot/efi for grub and /efi for systemd-boot.
While there is nothing wrong with using /boot as the EFI partition location, there is also no good reason to do so when using kernel-install. Doing that just puts extra files in the ESP.