Updating boot support partitions for the volume signs of internet dating scams
It support boot images up to 32MB, our have 56MB (which includes 40MB of initrd.img).
"El Torito" boot catalog structure have 16-bit field for image size (expressed in 512-bytes sectors). If bigger is used, the field will be silently truncated and only part of the image would be loaded by UEFI firmware.
I've found that out looking at hex dump of boot catalog...
Then would also use that truncated size for partition size, so even when this structure isn't directly used, the image would also be truncated.
Fedora images doesn't have this problem, because kernel and initrd is loaded by grub, so do not need to be in EFI partition (grub has ISO9660 filesystem driver).