Relapse is real. The majority of the companies we worked with saw significant improvements in site speed and/or user engagement. However, 30–60 days post consultation (when we were no longing looking over their shoulder) we would see bad habits resurface. To avoid this pitfall, use a performance budget. I also, recommend using the Chrome Dev tool to find unused CSS and JS code with the Coverage tab. When you load or run a page, the tab tells you how much code was used, versus how much was loaded. You can reduce the size of your pages by only shipping the code that you need. It is critical to monitor and audit your mobile site on an ongoing basis.