powerscreens.rpy has been implemented since the start. That's the pop-up when you're offered a new power to accept or not.
You're right about charscreen.rpy though, the code to display powers info on this screen hasn't been implemented.
It's not a mechanic issue. Frankly the occasional acquisition and use of the powers are one of the few times anything interesting happens.
The problem isn't the mechanic, it's buggy code to transfer stats between episodes. Players stats get nuked when moving between episodes, which means they subsequently don't have good enough stats to get later powers.
The game over is intended for people who
chose to reject powers when offered. With the save transfer bugs it catches unintended victims.
These episode transfer bugs have been fixed by the devs, and are freely available
You must be registered to see the links
.
So the solution to your problem is to download episodes 1-4 from Patreon and play through them again. To avoid taking 2 days again, just hit the Tab key. Since you've already played, it will skip through everything until it hits a choice, dialogue you haven't seen before, or an episode end. Doing this you can play episodes 1-4 in minutes, because there are barely any choices in this game.
This is a recurring issue in this thread. It's a mystery why f95 refuse to update the episode 1-4 download links to the fixed versions on Patreon. They have been reported in the past but rejected.