Speaking of mines. There's an idea to add a randomly generated landscape inside this object. Considering the wide variety of mountain generation, each mine capture will be different from the previous one. Besides that, capturing it will become impossible at speeds 9-10. For example, on an info map, I barely managed to micro 70 iron golems, and not without losses (due to the terrain, some golems managed to go around the mountain, while others didn't, sometimes resulting in a situation where they were all spread out and reached any point).
In other words, with such a fix, it won't be possible to get a convenient construction squad here, no matter how hard you try.
But yes, I didn't take into account many factors (for example, how it will look with several filled stacks), how much more difficult the capture will become for a regular army, and most importantly, what is the complexity of the technical implementation(?).

However, as it seems to me, such a change would fit perfectly into the game, and this addition would not break the canons of the classic game.