I run nginx 1.9.12 on Freebsd 10.2. (waiting on 1.9.13 to be in ports!)

What follows is my nginx.conf as it exists currently. To disable brotli, I commented out the module line and two configuration lines.
(likewise, when I enabled it, I did the reverse)
I did not disable gzip when I enabled brotli.
I compile nginx out of freebsd's ports collection as nginx-devel.

======================================================
#load_module modules/ngx_http_brotli_filter_module.so;

worker_processes       3;

events {
    worker_connections 6144;
}

http {
    include            mime.types;
    default_type       application/octet-stream;
    sendfile           on;
    tcp_nopush         on;
    tcp_nodelay        off;
    client_max_body_size 20M;
    server_names_hash_bucket_size 256;
    access_log         /dev/null combined buffer=32k;
    error_log          /var/log/nginx/error.log crit;
    server_tokens      off;
    ssl_session_cache    shared:SSL:45m;
    ssl_session_timeout  45m;
    ssl_ciphers ECDHE-RSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES256-SHA;
    gzip               on;
    gzip_comp_level     5;
    gzip_disable       "MSIE [1-6]\.";
    gzip_types         text/plain text/css application/x-javascript text/xml application/xml application/xml+rss text/javascript;
    gzip_vary           on;

    #brotli on;
    #brotli_types       text/plain text/css application/x-javascript text/xml application/xml application/xml+rss text/javascript;


    proxy_redirect     off;
    proxy_set_header   Host             $host;
    proxy_set_header   X-Real-IP        $remote_addr;
    proxy_set_header   X-Forwarded-For  $proxy_add_x_forwarded_for;

    index              index.php index.txt index.html index.htm;

    include fastcgi_params;
    fastcgi_intercept_errors on;

    server {
        server_name    _;
        root           /usr/local/www/nginx-dist;
        return 403;
    }

    include sites/*;
}
========================================================

What follows is my site configuration (the one which was de-indexed from google upon enabling brotli). I'm not sure if it is relevant, but I'm including it just in case.

========================================================
server {
  listen 443 ssl http2 default_server;
  listen [::]:443 ssl http2 ipv6only=on default_server;
  server_name explodie.org;
  client_body_timeout 15s;
  client_header_timeout 15s;

  ssl on;
  ssl_certificate /usr/local/etc/nginx/certs/explodie.crt;
  ssl_certificate_key /usr/local/etc/nginx/certs/explodie.key;
  ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
  ssl_buffer_size 8k;
  #ssl_ciphers ECDHE-RSA-CHACHA20-POLY1305-SHA256:ECDHE-RSA-CAMELLIA128-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES256-SHA;
  #ssl_ecdh_curve secp384r1;
  ssl_prefer_server_ciphers on;
  ssl_stapling on;
  ssl_stapling_verify on;
  ssl_trusted_certificate /usr/local/etc/nginx/certs/ssl-stapling.pem;
  resolver 208.67.222.222;
  keepalive_timeout 230;

  root /home/explodie/www;
  error_log /home/explodie/logs/explodie.org.error.log error;
  access_log off;
  
  add_header Cache-Control public;
  add_header Cache-Control stale-while-revalidate=7776000;
  add_header Strict-Transport-Security "max-age=315360000; includeSubDomains; preload";
  add_header x-dns-prefetch-control on;
  add_header 'Timing-Allow-Origin' '*';
  add_header X-Frame-Options DENY;
  add_header X-Content-Type-Options 'nosniff';
  add_header X-XSS-Protection "1; mode=block";
  add_header X-Permitted-Cross-Domain-Policies 'none';
  add_header 'Access-Control-Allow-Origin' 'null';
  add_header 'Access-Control-Max-Age' 315360000;
  add_header Content-Security-Policy "default-src https:; style-src https: 'unsafe-inline' 'unsafe-eval'; img-src data: https:; object-src 'self' https:; referrer no-referrer; reflected-xss block; upgrade-insecure-requests; block-all-mixed-content; frame-ancestors 'none'; form-action 'none';";
  add_header 'X-Meta' 'This HTTP response is now DIAMONDS';
  add_header 'X-NSA-DNT' 'DONOTTRACK';
  expires 3M;
  etag off;
  autoindex off;
  charset UTF-8;

  error_page 404 /404.html;
}

=============================================================

Compile time modules enabled:
IPV6, HTTP, HTTP_CACHE, HTTP_REWRITE, HTTP_SSL, HTTPV2, BROTLI

probably not relevant, but I use the openssl from ports, not freebsd base. (currently openssl-1.0.2_11)