Hello @efoley. We use a mix of supported and non-supported custom code. Some was written by internal developers on our website/marketing team, and some was written by my team, Customer Education.
The result is a functional but kind of messy set of custom code. Editing it can be a bit of a pain because it’s maintained by several people, many of whom lack web development experience. However, we have not yet encountered any significant issues that have impacted the site’s usability.
I recommend backing up your snippets to GitHub for tracking changes and keeping a copy outside of Skilljar, as it does not have backup and restore functionality.
Having a copy also makes it a bit easier to test your changes on a sandbox or staging domain. Unfortunately, Skilljar also lacks a straightforward system for testing these theming changes in a proper staging environment. However, you can simulate one by using a separate theme and domain for testing.
Happy to answer any other questions you might have on the topic.