OpenCart 3 – Mobile Speed Lag with Hero Slider

I’m working on my OpenCart 3 site https://blindsabudhabi.ae/
and running into mobile speed issues. My homepage hero slider is key, but it’s slowing down the page — PageSpeed flags high TBT and slow LCP.

I’ve tried minifying CSS/JS, caching, lazy loading, and deferring scripts, but it’s still laggy.

Has anyone managed to keep a big slider on OpenCart 3 while improving mobile performance? Tips on handling third-party scripts or optimizing sliders would be really helpful!

Thanks 😊