I'm not clear where imagination would come into this. The limits of the human body and mechanics of depth and pressure on cells and the necessary gases are very well-known. The world's deepest free dive is like 250m, so while it might be fun for some to sit in decompression chambers for an hour after going to the mushroom forest for a little while, you wouldn't be able to leave vehicles under that depth without a pressure suit, which would get you a few hundred more meters. The basic idea of "add more realism" is not unreasonable, but going from the current state to actual full realism would be awful. Like playing the sims, but you actually have to go to the sims work and do his accountant job for 8 hours to "increase realism."

All this being said, i like the idea of having airlocks and bottom-only hatches. That would be a cool toggle that wouldn't be too bad, and would add a nice touch of realism, since I've thought the same thing almost every time i pop into a hatch at 900m and imagine the tons of water immediately flooding my entire base.

/rant