Is it permissible to adopt the view of a trustworthy scholar if it contradicts the preponderant opinion and evidence, for the sake of desire rather than necessity?

A person is in one of two situations: Either he is knowledgeable of the proofs and methods of deduction, in which case he must act upon what he deems preponderant, based on Al-Shafi'i's statement: "People have unanimously agreed that if a Sunnah from the Messenger of Allah, peace and blessings be upon him, becomes clear to someone, it is not permissible for him to abandon it for the statement of anyone else." Or he is an ordinary person (a layperson), in which case it is permissible for him to choose among the Muftis, without intending to follow concessions or personal desires.