I suggest adding an upgrade to mining via the bucket wheel excavator. How i envision it working so it doesnt break the game, You can assign one bucket wheel excavator per mining tower, if you have one assigned to a mining tower you cannot have any other type of excavator assigned. the vehicle would cost 10 spaces and its crew requirement would be 3.
Bucket Wheel Excavator
Maybe we could use the rail mechanics to have it as a part building part vehicle instead.
Starting with a depot to build, house and consolidate mined material.
Rails extend from it to allow for limited straight line movement. Maybe as a unique set of rails that can only be payed straight. Comes with a built in loose conveyor.
Distance can be limited by a maximum rail length or by increasing costs of the rail / maintenance.
Size should be scaled to be more inline with in-game I suppose.
This feels like it should be a seperate suggestion lol.
I think doing it like the stacker tower would make sense as well, it's proven you could already have it auto expand, so set it by the tower it can do an area so far right and left, and maybe do 5-15 tile depth for mining, but as it clears an area it auto expands out and leaves conveyors behind it to move the material back to wherever and consumes Rubber, Steel and Construction parts to build new sections.