Hey Xanthos, 11520x2160... wow
You can control the horizontal size of the window, yes, but that will naturally require using windowed mode. I don't believe it's currently possible in fullscreen. However, using windowed mode would add the title bar and therefore reduce the font size one step, to 32x32. I can help you set that up if you like. (Basically you just switch to windowed mode, and while Cogmind is not running you can open user/cogmind.cfg and edit the mapWidth value to reduce it.)
Now that we have borderless windowed/fullscreen mode, I may be able to rig that to allow different widths...
looks very nice in 36 font @ 11520x2160, though the menu spacing's a bit off far to the right.
Could you attach a screenshot so I can see what you mean? (And I guess you have your screens set up in some special way? Myself and others play as normal on our multimonitor setups, with Cogmind on only one monitor.)
And I can imagine there are performance issues with that massive screen area--that's... a heck of a lot of terminal cells to render! The evolution screen in particular is a lot of particles moving around if you've got the space for it.