JohnK,
Can you verify that the following Registry Key is on the PXE Rep.
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Intel\PXE\Mtftpd\Files\ ia32 efi\\undi\\bstrap\\bootia32.0"="224.1.5.8
If not your OSDRep.msi file did not get updated properly on the core when you installed the 228A patch. You'll need to manually grab the OSDRep.msi out of the directory you extracted the 228A-BASE patch to. Place on the core at "\Program Files (x86)\LANDesk\ManagementSuite\LDLogon\OSDRep.msi". Just rename the original file in that location.
Once that is done redeploy your PXE Representative, and try UEFI booting the device again.
Let us know what you find.
Thanks.