Unfortunately, Android has always been a red-headed stepchild to Unity. Not to mention, the different hardware configurations also make it more difficult to optimize for. There was a good blog post recently about optimization though: Tackling profiling for mobile games with Unity and Arm
By the way, as the main lag comes from the instantiation of the same prefab thousands of time to make the hex map fo the game, do you know an article tackling with this ?
No but if you’re doing it ahead of time as like an object pool, you might be able to cleverly hide it like in an intro scene. You might also want to consider reducing the number of instances, to that which is on screen.