Hi all,
Good news - the E5-2667 worked absolutely fine out of the box - the board arrived with the 1104 BIOS. All of my 8GB DDR3 DIMMS were detected too without issue.
After finding the Arctic Freezer 33 Plus being too fiddly to install, I initially used an BXTS13A cooler that I bought for the i7 3820 that came with the board. Oddly, it was idling at 55C on the first evening I got the machine up and running. By the second evening, it was running at around 42C - much better. However, I really wanted a proper Xeon cooler, so have now installed a SuperMicro SNK-P0050AP4 cooler. Temps are the same as the Intel cooler.
I initially had issues with the graphics card driver crashing under Windows 10 - it's an AMD R9 380-based card. Last night, I flashed the board using the BIOS Converter and then flashed to the 4107 BIOS. Cleaned out the AMD drivers and reinstalled version 18.51. So far, all is good and the system feels smoother and more stable after the BIOS update.