Only if you take the one you want to release before the other.
The question on ERAS is something along the lines of "release USMLE transcript changes without requiring reauthorization?"
So if you take ck before cs (or vice versa), you can release one without the other. However, you cannot select to release one but not the other if both scores have already been posted. If you want to release only the CS or only the CK, then make sure you are going to get your score report for the respective test before the one you don't want to release.
Personally, I released step 2 ck when it came back (took it first), then once my CS came back i released it as well.