The phrase "most backstairs" implies something secretive or hidden, but its antonyms suggest openness and transparency. Instead of being covert, one could be more forthcoming, outspoken or frank. Similarly, instead of being underhanded, one could be fair, honest, or forthright. If one wants to avoid actions that are seen as sneaky or elusive, they can act in an above-board manner with transparency and by being forthright. Expressing oneself more directly, openly, or candidly may the perfect antonym for the phrase "most backstairs," allowing one to avoid any confusion and mistrust.