On my previous server, I had an installation of my UniFi control panel on the same server as I had setup with my previous mail/dns/webserver config software and they worked well alongside each other. Is there any reason I should or shouldn’t be able to do that with Hestia?
Basicly you can try it, according to our system requirements we suggest to use a blank system only: https://github.com/hestiacp/hestiacp/blob/master/README.md#supported-operating-systems