CJLukez wrote:
Thanks again. I'll try those suggestions out.
Regarding the Linux boot, do you know how to change bootloader folder and file names to get it work?
You just need to mount the hidden EFI/ESP partition (usually the first partition on the drive) and change the name of the Linux bootloader folder & bootloader to "boot/boot_x64.efi". Usually Ubuntu will have "ubuntu/grub_x64.efi". When you mount the hidden EFI/ESP partition, I believe there will be an "EFI" folder which will contain the "ubuntu" folder I mentioned.
Keep in mind by changing the names, anytime Linux updates these files, that your "boot/boot_x64.efi" will not automatically be updated (it will probably create another "ubuntu/grub_x64.efi" setup). To have Linux use "boot/boot_x64.efi" as the default after updates would require modifying your Linux installation configuration files. I'm not sure how or where to do this, perhaps with the GRUB2 configuration files. Unless you are modifying things after the installation, I doubt it will really matter since I don't believe the bootloader files are updated very much. Just something to keep in mind though.
Some Macs seem to work fine with these distribution custom names, while other Macs seem to require the more generic "boot/boot_x64.efi" option. Thank Microsoft and the Logic Boards' UEFI firmware developers for being so cheap & short sighted. Apple relies on "blessing" the bootloader to indicate which file to use, but as far as I can tell "blessing" only works on an Apple file system (HFS+ or APFS), not on FAT which is what the hidden EFI/ESP partition uses.