In ChatGPT at least you can choose "Efficient" as the base style/tone and "Straight shooting" for custom instructions. And this seems to eliminate a lot of the fluff. I no longer get those cloyingly sweet outputs that play to my ego in cringey vernacular. Although it still won't go as far as criticizing my thoughts or ideas unless I explicitly ask it to (humans will happily do this without prompting. lol)