TELUS websites should have excellent search engine optimization. On search engines like Google, performance plays a big role in gaining a high SEO rank. TELUS developers are strongly encouraged to maximise performance in order to make high gains in SEO.
Unused CSS is a detriment to SEO. Some basic optimizations and insight are covered and referenced in the CSS reference architecture.
In your applications, only include the CSS or SCSS you need from TDS. This can be further maximised by adopting styled component methodologies.