It just occurred to me but I don’t know if it’s any use, it’s just a concept 
Link: Hestia Control Panel
I have added:
Or modify your installation with for exmaple:
bash hst-install.sh --apache no --postgresql yes --clamav no --spamassassin no
Will install Hestia without Apache2, ClamAV and Spamassassin How ever it will install Postgresql as additional feature
More options or examples can be found in the Documentation or use the Install string generator
To the home page including a better way to generate the install string.