While the xf_css_cache table is subject to 'thundering herd' issues; it still provides a benefit during cache rebuilds and the frequent invalidation is a XF issue with it's usage
Implement short (~5 minute) caching of individual css templates & parse_less_color/parse_less_func functions (parse_less_func is from Advanced BbCodes Pack). Minor, but measurable performance improvement
When caching is enabled, this hits redis instead of the xf_css_cache table.
