I have a one large terrain that encompasses the whole map. This is generally a waste since most parts of the terrain are outside village, wasting precious frames. I have split up the terrain into many smaller chunks. According to my testing, it is also much quicker to terraform a small terrain than terraforming the same sized small chunk in a large terrain. In other words, this should make terraforming much faster and perhaps allow me to animate it.
I have a system to not render objects if they could never be seen. This increased performance greatly, but the system could be improved. I redid the entire system to utilize Unity's amazing Job Burst system. The code is truly black magic but the 20fps increase speaks for itself.
There's a couple of other things like removing some shader casters from the small props, which should improve performance a bit more as well.
There's also an essential (but tedious) thing where I could combine walls in one single mesh. This can greatly reduce the draw calls which always means more performance.
I should also look into improving my shader code but I don't know where to start tbh.
Also, I need a new system to keep track of the amount of destruction, and to force a limit on how much destruction can exist at any given time. This should improve the lag spikes that occur during the end game minigame.
And then there's fixing my terraforming code to these new systems, which I haven't done yet. It shouldn't be hard, but refactoring code is always scary.
That's everything I am currently up to. As you can see, very little room for the GTS (besides animating footstep hills).