This is a recurring problem. Even most of these games that allow for custom controls have so many bugs around them it's not worth it.I have to commend the ability of this game to be played with only one hand. Wasd, qezxc, done, you have all game controls tightly packed in a small area of the keyboard.
Which is why I use Autohotkey for basically all of these. Especially handy for stuff like RPGM & Ren'py since they all have the same defaults. It just seems so insane to me that basically every single h-game dev has the skills to make an actual game, yet can't figure out how to make accessible 1h controls when I can script them in in less than a minute. And I'm no tech wiz or a dev at all lol.