Yep sadly this is the case. When we implemented Reflection (as a pointer to deck manipulation, which we decided not to do for complexity issues), I wanted to do secret hands to go with it. Since it was just for one sigil, it was a "nice to have" feature that we had to cut for time. Discovering Balatro's secret hands for the first time was a wonderful experience.

We started with a flat heal, and effectively it would create "doomed" game-states a lot more commonly. A player would either be at low HP the entire game, or be at nearly full. A big requirement I had was that about half the players who would play Story Mode would be able to complete it (with Hard and Demon being harder / more reliant on creating a synergistic build). Ultimately, pushing to a percentage-based heal helped rubber-band players who were behind to get a chance to keep progressing until they found their sigil build.

It is, however, one of the core flaws in my tuning, and a sign that I somewhat ran out of time to make sure the harder difficulties were fair enough but ALSO hard enough. I opted for "easier than I, as a player, would like" to make sure as many players as possible could get the icon and the title. We played a bit with making the heals different values on different difficulties too, but ultimately made the call to just keep it consistent.