TL;DR
Many people want an easy way to toggle things like personal robots. The question is where to put it so the UI doesn't overload you with information. The pickaxe slot is perfect for this as the pickaxe can be removed from the game with no loss.What ?
a: Removing pickaxes.The pickaxe is completely removed from the game and made default instead. You'll mine at the speed of a steel pickaxe already from the start with the same animation as if you had it.
b: Adding toggle menu in its place.
Similar to power armor right clicking brings up a toggle menu. The toggle menu would have toggles for all applicable power armor equipment (and may I suggest belt immunity to be made vanilla too please: https://mods.factorio.com/mods/magu5026/BeltImmunity). You should also be able to assign a hotkey to each toggle. Other things also suggested in this sub forum could go into that menu.
Why ?
The pickaxe is not very interesting. You get it and it's just there. You get a small upgrade very early in the game and then nothing ever changes ever again.The slower pickaxe in the beginning is just wasting your time being slower. It doesn't add difficulty, especially not now when they are stackable. The sense of progression you get from acquiring the steel pickaxe is so minuscule that it alone does not make the whole system worth it.
Toggling power armor abilities on the other hand is something many people want, and that square is perfect to use for a graphical representation of this as it is right above the power armor.
I have seen people suggest other controls as well, to go with their specific suggestion. I am often negative to that because I don't want too much info on my main screen. However this menu could be used for them as well (if implemented), like a control hub.
