VPS are low-powered with limited/less resources. Instead, get a dedicated server with good specs at reasonable price
Optimize the server security/speed for PHP, Nginx, PHP-FPM, MariaDB, etc
Cloudflare Pro with optimized settings and WAF enabled
Redis
Web-API for outgoing Emails
It isn't the issue with Cloudflare, so you're users will see the live updates without cache problem.
There's already a setting in IPS software to compensate that.