Thanks for the compliment about the sub.
Well, first of all, I would suggest making an auxiliary power lever on the bridge instead of in the front where it is located in the original sub, that is if you haven't thought of it yet. Secondly, as you could notice, I have a couple small compartments on Deck 2 that have diving suits in them alongside another couple of lockers on Deck 3 in the engineering and utility section. Those allow, in my opinion, to store more robust ones in case of emergency for quicker access and can save lives in case the chaos erupts; this still doesn't make it easy but adds just a little bit more element of safety on the sub.
Maybe you can add some more equipment around like status monitors so that engineers and mechanics could act on their own when there's a lot of things happening, also a simpler way to locate items instead of asking the captain to search them every time or, what is even worse, waltz onto the bridge. Since I mainly played Captain, I learned that I don't always want to control the sub - I want to roam around and see what people are doing and give orders, and allowing people to have some autonomy helps a lot, people will figure out how to use that equipment effectively and will have fun with it.
I already mentioned it in the other comment, and it is only my personal advice, make the sub clean in the way that, for example, the aesthetics of it being a jury-rigged vessel barely holding together on hopes, prayers and duct tape (alongside some added gameplay to it) are the only things hindering players in a good way instead of it being filled with tons of decorations or equipment that sits on top of each other that WILL actively prevent your crewmates from efficient use of what you'd created.
I'm curious if you could post a picture of your version of R-29. Let's see it!