3d Header Remove Space Between Buttons

Would really like to get rid of the space between buttons in my 3d Viewport header. Can definitley add more space by using sub.ui_units_x but unfortunately it doesn’t go below 0 to take space away.

Playing around with space_view3d.py to make it smaller, changing buttons around. For example, the button next to overlay dropdown toggles the grid and x y axis guides instead of everything possible, and the button next to the shading dropdown cycles between solid, material, and rendered.

Trying to make it as small as is reasonable, so I can put some more buttons in there. Stuff that is important enough not to go into the collapsed menu for, but not important enough for quick favorites. Still a long way off from working out what those things will actually be, but want to tidy this up a bit.

I am guessing I will have to edit something in the c source, but maybe this is possible with python?

Getting somewhere. Can remove the header offset, the empty space in the far left side only, by changing line 1005 of UI_interface.h

Still nothing for the space between buttons though

Ok found it, it is in interface_layout.c, line 2807
x += itemw;

change to
x += itemw - 5;

Not sure if I will keep the headeroffset at 0, because as you can see it affects every header, depends if I want the space for an extra button or two. I will glady sacrifice some form for function. Proportional edit buttons are a special case, probably something to do with icon_only. Don’t care really, can always put it on the end to diminish the effect