Are you trying to boot UEFI only (no BIOS emulation) or are you trying to do something like BIOS for 32 bit systems and UEFI for 64 bit systems?
I'm interested to hear how you make use of UEFI and why you need 2 different boot files.
In my environment, we had WDS for a long time but moved over to Landesk provisioning less than a year ago and love it. We keep WDS as a backup and also use it as the PXE boot server host (DHCP option 66)- we don't use Landesk for PXE. All clients support BIOS emulation so we just kept DHCP 67 as default boot\x86\wdsnbp.com and we added the Landesk 64bit WinPE image to the WDS boot file menu.
FWIW I think I've rebooted the WDS server once in 8 years- it's very reliable re serving up PXE boot images.
With this setup we do zero-touch bare-metal builds (HP workstations & Lenovo laptops / Win10 x64) now with hardly any errors and are very happy with it. But there's always more to learn, so interested in what you are doing if you care to share.