I think being a "creationist" and not taking Genesis literally are incompatible. A person who believes God created the Big Bang and gave the spark of life to creation isn't, IMO, the same as a person who believes God created the Universe in 7 days, Adam wholly formed and Eve from his rib. The latter would be a fundamentalist Christian not seeing the situation using critical thinking. The former would be someone who is using critical thinking but with a belief in the supernatural.
I potentially could accept that there is a "creator"
but such has not been detected as yet.
Belief that there is, is entirely a matter of faith.
Critical thinking exists in a climate of doubt, not
faith in a foregone conclusion that lacks all
supporting evidence.
Our "believer" may well, probably does use CTS
in other realms of life, but has to wall "god" off
from it.