The basic variables, such as thickness, should be user-entered. As it is, the time/temp calculation is wrong if the thickness of the meat you want to cook differs from the offered value.
Instead of using the Baldwin formulas, where ingredient, thickness and bath temperature calculate the time to reach a core temperature, we wanted to offer adjusted recommendations. Food is never an exact geometrical shape and waiting for an extra hour for a piece to reach an additional half a degree is impractical. We hope that our adjustments for speed and efficiency improve the Sous Vide experience. In Release 3.2 you can now set your own timers. We are looking into more ways to allow users to enter variables.