Booting Legacy Linux Install (MBR) with OCLP?

I have OpenLegacyBoot.kext and and ext4.kext installed but it does not see Legacy Ubuntu install. Can I boot Legacy (MBR) installed Ubuntu with OpenCore? I have Ubuntu installed along with Windows Legacy because my computer has a hybrid EFI, not true UEFI so it can't boot Windows UEFI. (MacPro 3,1) Windows and macOS show in OpenCore bootpicker, however. Can I create a custom boot menu entry for Legacy Linux or will that only work for UEFI installs? Thanks!