Easily detachable rope is used in places that probably don't need permanent blocking, but a more permanent handrail is built on the deck where people would want to walk through. There's more than one way to solve this - maybe the handrail has a gate and the ropes are also handrails? Also consider extending the boundary out to the entire deck instead of blocking it in the middle (and add a roof if the handrail doesn't feel complete as a level boundary).
See if you can get away without any electrical lighting in this space (or, rather, only use it where necessary). Realistically, if the sun is only just coming up/down the lights might still be on, but using just natural light in an interior space is a unique lighting condition that not a lot of maps use.
Another note on lighting: Getting light cones to appear on walls can really help make lighting feel less bland. Moving your lights close to walls (and also centering them over a doorway) is a great technique.
Last note: Add stains.