Difficulty/realism modes?

What actually changes when you pick the harder crew management/ combat difficulties?

I know for combat you have to do the calculations yourself ( I do know how to do this from playing iron wolf but this is a little hardcore for me )

But what other stuff changes?

The way the game is right now (medium on both)

It feels like I’m time jumping way too often

don’t really have to think about the convoys current heading too much I usually just surface get parallel to them, full speed, and get ahead, then approach again at periscope depth, but by the time I do all that they definitely should’ve seen me already.

I have a dive schedule but I usually run into convoys by seeing their smoke plumes first. Which you would think makes sense since the convoy is so big with much bigger smoke plumes you should see them before they see you, but I think realistically they have so many more eyes out on the water and they are at a much more elevated position that you should see each other at about the same time but I can usually be a few kilometres from a convoy in broad daylight and they don’t bat an eye

I want the game to be a little slower and more difficult but also not be too hardcore like doing the torpedo calculations myself what do you guys recommend?