Many people don't like C2's streamlined suit option, or maybe they have another idea for how it could work in C3. I myself have a sort of complicated idea of how this could possibly work.
Here's a crappy diagram I drew(things are subject to constructive criticisms and change):
Now, I'm going to explain the diagram and the numbered boxes.
There would be 6 spaces that open up and for PC, this would be mapped to a key. For consoles, I still haven't decided yet.. Which is a problem. It could be customized in the pause menu?
Anyways, the top 3 options are the main customizations for playstyles. The top hexagon would be the streamlined version of controls, basically where power and speed are the same. The top right, for example, could be the C1 playstyle, with armor as basic mode. If there is only one default mode, then either the r2 or l2 could have double modes, which you would press and then topggle with the joystick and whichever side (left/right) is pressed is chosen. The bottom three could be specialized modes where it's either all power, all speed, or all armor. I'll give a few examples. If you need to get up a cliff quickly, you can either go all speed to run up the hill, or all power to say, jump up the cliff in 1-2 jumps. In another situation, there could be some kind of bomb, and it's extremely heavy. You can either go all speed, and get away in time, or go all power to pick up the bomb, and throw it extremely far away. Finally, you can go all armor where it would take maybe say, double to triple the power of normal armor, and tank the blast.
If these specialized modes, the abilities that are specialized are increased many times (undecided) and drain energy faster. The downside is that all other modes cannot be used, so these are for usually non dangerous situations where you aren't in a fight, or you are say trying to fully escape something or say, punching through a wall.
Anyways, those are ideas of mine for both suit interface and for modes that could be implemented in the game. You can either critique one, or both together. The specialized modes/suit playstyle don't necessarily have to be together with the interface, so don't think that it won't work completely.
EDIT: Other ideas are also welcome, or perhaps an adjusted version of my idea. This is for all ideas for what you want for C3's suit customization.