In the kits that I've seen, a spacer of equal thickness is added to the oil pick-up tube as well .
There is another variant of the spacer, that has tubes cast into the spacer that run front to back, to allow cooling air through the spacer, to help cool the oil .
I was considering this variation before adding the OEM BMW oil cooler kit, then found out, that the center stand wouldn't clear the oil sump afterwards, at least, with the Luftmeister kit .