Thanks.
I only have a 1080p screen myself, which is why the mod is made to fit 1080p screens.

It's not hard at all. To be honest, I was a complete modding noob when I began making this.

Extending the interface takes two steps.
The first step is to extend the background. To do this edit the .dds files located in "...\gfx\interface\". To edit them I use GIMP and this plugin[code.google.com]. The gfx for the character finder is charbrowser_bg.dds, and the character selector (ex. apointing advisors etc.) is charselect_bg.dds. Note that you also need to edit the gfx files in the subfolders for muslim/pagan/indian interface (for the char finder indian interface uses the muslim one).

Step two is adjusting the placements of the different UI elements. This is done by editing the .gui files located in "...\interface\". I recomend using notepad++ or similar to edit. By using the console command "guibounds", you will get info on file and line for each ui element. You can edit the .gui files while running the game, and updating the changes by using the console command "reload [file name]".
The file domestic_characters.gui governs the character finder, and the file character_selection.gui governs the character selector. To add 3 more characters you need to edit the y size value inside "windowType = { name = "character_list" ".

The interface is adjusted by pixels, with scaling enabled this pixels are "stretched" (I'm no programmer, I don't know exactly how the scaling works) hwich means there is no longer a direct 1:1 ratio. This isn't a problem, just meaning you have to test by trial and error which value fits best.

When reaplying changes after an update, using winmerge is very helpful. And if you make your changes in a separate submod you changes won't be automatically overwritten when I push an update. whan making your submod add the line "dependencies= {"Bigger Interface"}" to your .mod file, this will change the mod load order, prioritising your files.

The best way to learn modding is just to experiment and test by trial and error.

Thanks for the info and the detailed response! I'll give that a shot!