I wanted to expose a solution that I found and understand if it is a monstrosity or a practice that can be right.
To largely solve the LCP problem I created a web page in php that loads only the first contained in the body and then, once the page has been loaded, in javascript it loads the rest of the of the page and puts them after the first one already loaded.
This solution to improve LCP seems useful to me but I have a problem because when I load plain html everything works very well but when I load a html which uses other javasccript for effects (fade in, fade out of elements on the page) the effects don't work.
From here I asked myself the doubt and then the question: is the proposed solution a monstrosity and therefore a road to be abandoned or is it a useful solution and therefore I have to study how to solve the subsequent bugs? Thanks for your advice.
first load <div 1> by javascript, on page load: load <div 2, 3, 4, etc>