> To optimize this, instead of scheduling a function call, we simply add the information to a Map - the arrival time, resource, amount, and target building. Then in the tickDots method, we loop through the map and if a resource has arrived, we remove it from the Map and add the resource to the target building. This reduces the frame time from barely under 16.7ms to a comfortable 11ms.

What you have implemented here is a priority queue, with O(1) insertion and O(n) deletion. It is easy to get down priority queues to O(log n) deletion without sacrificing insertion speed noticeably much. So unless you have some good reason to iterate all resources every iteration, changing to a better priority queue implementation will most probably yield you even more of a benefit.