Comments on the site to be indexed and not slow down the download speed?

Question

Web development

You need to add the ability to comment on the site.
I am looking for a solution that will not worsen the download speed according to google pagespeed insight, will be indexed by search engines and will have great authorization capabilities.
I assume that you need to load the texts of comments immediately, in order for the search engines to index, but the authorization and submission form should be loaded on scroll or click. Then the download speed will be preserved and there will be indexing.
Does anyone have experience with comments like this? Perhaps they used some kind of system like disqus, cackle or others?

Answer 1

Maybe Commento will suit you - https://habr.com/en/post/446786/