PrestaShop speed work starts on the templates that take money: home, category, product, checkout. A lab score on an empty demo is not a diagnosis. I do not publish invented 96/100 badges.
A practical order
- Measure field or lab CWV on mobile for those templates.
- Find heavy modules, uncompressed images and blocking third-party scripts.
- Enable a cache that survives your checkout and cart, not a cache that breaks cookies.
- Retest the same URLs on a phone. If checkout got slower, the cache is wrong.
Server PHP workers and MySQL matter on large catalogues. A new slider does not.