I'm all for optimization too, and you can find my thoughts and some techniques in this tutorial
, but as Ashley pointed out in this blog article
, events logic won't be a problem in most cases, as the rendering is usually the limiting factor of framerate.
For the typical case you described (+1 every X seconds, do once this event when hitting a fixed goal), I prefer to go with recursive functions. They give you a good control over the situation, and they are trigger-based, meaning they won't be evaluated every tick for the rest of the runtime.Here
is an example of how I usually do it.