I was about to post something too, I second the visual bugs at least. I can understand that because the cell wall passes air, light and sound that the room is not separated anymore and thus could be seen as part of a barracks. It's balanced in my opinion, but maybe an option to toggle it would be good.

Please at least fix the texture alignment issues though. Not just doors, but connecting walls are also inconsistent: https://ibb.co/6cMNxb39

I could imagine that you could work around the visual bug if you extend the separator wall between the cell. A cell wall next to a door always wants to align with a wall on the opposite side from the door. If you place an actual wall there, you might be able to hide the bug. I also have a 3 wide cell, yet I placed the door on the side, not in the middle, so the middle cell wall is misaligned.

Cell wall

About the balancing, I agree. As far as I know, there is no block in vanilla that's both a wall yet lets everything through. So I could imagine that's the reason why cell walls can't do that.

But it would be gold if it's simply a bug and could/would be fixed.

Thanks, that's what I ended up doing, it's a good workaround until if/when it's fixed. Also, as long as the wall is only 3 tiles long and you put the door in the center you don't get the janky walls at all, which will work in your prison too: https://ibb.co/Fk2LqfdM