Since Windows 10 becomes an unsupported OS next year, I re-enabled secure boot on Windows 10 (via the BIOS settings for my motherboard) so that Windows Update would let me perform the update to windows 11.
Once that had all completed, I disabled it again and my machine now boots into Windows 11 and still lets me use my Xeltec 280U programmer.
Because I updated from Windows 10, the system setting for Core Isolation – Memory Integrity was disabled. If you do a clean install then this defaults to enabled – This needs to be disabled for the EZUSB driver to work.
Click here to see full information and download the necessary files.