I believe I added this as the recommendations I had read said to set this very high in production: 
https://groups.google.com/forum/#!topic/requirejs/RTMggsZq7aw

Requirejs allows scripts to be (a) modularized and (b) loaded asynchronously at webpage execution, by dynamically loading in script modules via AJAX as needed. This is useful for large codebases, however, we only use it for (a) and in our setup all the modules are combined together and minified and run through the rails asset pipeline. If we used (b), the `waitSeconds` becomes important for the loading of our scripts. However, since we don't, I can't quite remember where this surfaced, but we probably ran into a timeout with the Google API related modules. These modules include an `async` plugin that should wait for asynchronous requests to JS CDNs, but it may only do that within the `waitSeconds` period. In production, we wouldn't want disruption to the JS just because someone was on a slow connection and gmaps was slow to load.

I've opened #438 for checking whether this timeout is necessary.

That technique with domReady is neat! Thanks for surfacing it. This would be for a script that's blocking the page load. We should really move the main scripts to the footer (with the exception of Modernizr, the polyfills, and GA scripts). I've opened https://github.com/codeforamerica/ohana-web-search/issues/439 for that.