Add keepalive in nginx configuration

Hello,
Why not add a keepalive 32 for example in the nginx configuration : https://docs.nextcloud.com/server/latest/admin_manual/installation/nginx.html . In the nginx doc, it is advised for performance issue : https://www.nginx.com/blog/tuning-nginx/ :

upstream php-handler {
    server 127.0.0.1:9000;
    keepalive 64;  # add this line
    #server unix:/var/run/php/php7.4-fpm.sock;
}

[...]

server {
    listen 443      ssl http2;
    listen [::]:443 ssl http2;
    server_name cloud.example.com;

    # dont forget to add these lines !!!!
    proxy_http_version 1.1;
    proxy_set_header Connection "";

[...]

Start with the nginx installation page at docs.nextcloud.com/server/latest/admin_manual/installation/nginx.html and compare its upstream and server examples with the linked NGINX tuning guidance. Confirm whether the keepalive and proxy directives apply to the documented setup; done means the page clearly reflects the agreed configuration or explains why it is not included.