Pity you can not specify 2 boot images...
regular
and UEFI files.
IE old disk Boot image , was done with Sysprep. however some of the wims are patched , however patching and shimming UEFI , a plus.
so far copy /b boot.ima + efisboot.com test-boot.ima... ?
since its for the cloud anyhow , trying to find a way to slipstream in UEFI into current loader , test before burning to an actual release Image.