Add ladders back to the interior passage block and the ceiling of sliding doors

If you add ladders back to the interior passage block then it can be used as a ladder passage when used vertically and still a walking passage when used horizontally. Two for one! Win, win!

Also, I build my ships like sky scrappers so they are tall instead of long, which means I have narrow ships that have vertically stacked decks like floors in a building. I use sliding doors between decks and ladders to move up and down but I cannot climb through the doors. If there was a ladder on the ceiling of the door like I just suggested for the interior passage block, this would solve that problem and also be a two for one solution with two existing models and functions combined into one.

Also, the ladder system needs some tweaking. It rarely lands me properly at the top of the ladder onto the block I am trying to exit on to, whether in gravity or not. Sliding down a ladder would be a cool feature. It was said that ladders could be used instead of scaffolding in survival building but this not true as you cannot weld or grind or interact with anything while you are on the ladder. So you would eventually have to build scaffolding or use jetpack to build a tall enough ladder or work on stuff up high.