The term "more unassumed" can be an ambiguous phrase as it is not always clear what is being referred to. However, considering the two terms within the phrase, we can explore some potential antonyms for each. "More," as a comparative term, can be contrasted with "less," "fewer," or "diminished." Meanwhile, "unassumed" can be considered the opposite of "assumed," "presumed," or "pretended." Some possible antonyms for the phrase "more unassumed" would be "less assumed," "fewer presumptions," or "diminished pretense." These terms would indicate a decrease in the level of assuming or pretending, resulting in a more genuine or sincere demeanor.