Thanks for the feedback! I appreciate it.
My intention for the step up/down of the test die was more along the lines of "just go by feel in each situation." Part of that decision was driven by the one-page limitation for the jam and trying to get the core mechanics on the front page. I'll try to cram in a little more detail somewhere in a revision.
That being said, I'm planning to either expand the game at some point and/or write a generic version of the system that could be applied to different settings. In both cases, I would probably include either specific mechanics for stepping up/down (e.g., one per trait) or more detailed guidance for GMs in setting the tension rating.