I am an old SH3 fan that finally has only come over to try sH5 in the last months or so.
I was really excited about the "moving around inside the boat thing" but for me, personally, I find that it has worn off and now I just time accelerate at 128 while looking at the map until my crew spots something. Then, during a hunt, I am usually on the bridge. What I am saying is I don't really use the inside of the sub much. It is great to have it but I just don't use it anymore.
Still playing SH5 with TWOS mod. Love those clouds and sunsets!