I believe as a User Experience Designer, our role is to research user's preference, likes, dislikes, or how usable a design is...no prototyping software has truly realized why UXers need a screen design software (unlike Photoshop).
Please implement a truly marvelous built in User Testing or Usability Testing platform for Protopie, where we can define missions, create success path, and share it with our target audience to gather quick feedback on our prototype and learn from our mistakes/shortcomings in prototypes to create a truly user validated design.
Please refer https://Maze.design
If you need ideas/suggestions or help in designing built-in User testing platform, I will be more than happy to help.