I struggled with it yesterday until the evening, but I finally did it. Here is the improved version of the mod with the ability to save. Please note that it is guaranteed to work in 1920x1080 resolution; it has not been tested in other resolutions!
https://yadi.sk/d/XmoHlcSq3Z2dC4
Guys, I have a question: the button is always in the same place, both on the strategic map and on the tactical map. I spent a long time analyzing the code, but I couldn't find a way to remove its display on the strategic map.