Target Opacity set to 3s. Optimal setting

We have our target opacity set to 3000ms, as default set on the body element. This is affecting the LCP (Largest content paint), and SEO speed of the website.

#1 ) How can we avoid flickering or have an optimal opacity setting that does not affect LCP

#2) Is 3000ms the adobe default?

#3) Has anyone have less than 3000ms and have an optimal LCP reading?

or should we set the opacity on a different element, to avoid flickering, but still have LCP load fast