Career Site Design - JavaScript event for Custom Header

Summary:

Does Oracle provide a JavaScript event which will fire after the "custom-header" Knockout.js component is rendered?

Content (required):

While my organization transitions our career site to the minimal template, we're working with a web developer to create a custom header that matches our existing navigation. The current solution leverages a combination of HTML in the Custom Header field, as well as code in the Custom JavaScript field.

The Custom Header code contains an element we need to use inside the Custom Javascript using document.getElementById(). The issue is that the Custom Header code is not rendered on the page immediately. i.e. Oracle platform injects it via Knockout.js after the page loads.