A quick google scholar search highlights a number of studies that provide reference on suggested upper (max) limits for pedal force requirements (often based on 5th percentile ankle strength as measured from a given population). The joint torque visualizer could be used along with a point load on the foot to determine the maximum point load that would be possible based on a 5th percentile population.
Based on a cursory review of the literature, fewer papers seem to consider how pedal forces might need to be further reduced to consider frequency of use of sustained used. To consider frequency of use, you could estimate the duty cycle for pedal use (based on how many pedal presses will occur in a given time, how long is each press sustained, and what the given time is), and then use Potvin’s Duty Cycle Equation to manually determine what % of maximum strength would be acceptable (referred to as MAE and Maximum Acceptable Effort). You could use Santos in a trade-off analysis approach to iterate the point load representing the pedal force until the ankle torque (expressed as a percentage based on female strength) was equivalent to the MAE calculated by the equation.
Here is a link to a conference paper that has applied this approach, but based on the use of 3DSSPP.
Potvin’s DC equation paper can be found here. This is effectively the same thing that happens within the Arm Force Field visualizer, but we apply it based on ankle strength instead of manual arm strength.
Alternately, you could consider this challenge from the perspective of static endurance, which can be done manually or using the static endurance visualizer available in Pro. You could use the equations published by Laura Frey-Law (see Table 2), to estimate the endurance time, based on the ankle torque required to sustain the pedal press. Using a trade-off analysis approach, you can vary the pedal force in Santos to explore how pedal force affects ankle torque as a percentage of strength, and then, in turn, use the updated ankle torque (as a percentage of strength) in the Frey-Law equation to update the estimated endurance time.