I love you @mrpink, thx!! I'll do tests the next few days and release a newer version
But please switch back to Unix Socket communication as default in the config.php, because it is really much faster then TCP Sockets.
The initial version of the ClamAV Plugin, which I developed together with @TheCry, was using Unix Sockets. I don't know who and when it was changed to TCP Sockets.
Think it was TCP Socket all the time? But yes that was also my plan to switch to unix socket (after some tests) 
No, it wasn't.
The last version I commited on 18th Feb 2014 it was Unix Socket. It changed to TCP socket on 12th Jan 2015.
So it was well testet and running with Unix Socket until Jan 2015.
The ClamAV plugin with Unix Socket is in production on my system since 2 years now.
So it is not much testing necessary.
Ah yes TheCry changed the values..
What's the difference between /var/run/clamav/clamav-milter.ctl and /var/spool/postfix/clamav/clamav-milter.ctl?
clamav-milter.ctl is the Unix Socket file and must be accessible for clamav-milter and also for postfix.
Postfix is running in a chroot environment and needs to pass the mails to clamav-milter to be checked for viruses. The following entry in main.cf is responsible for that:
And as you can see, the path is here different, because postfix is running in a chroot environment (/var/spool/postfix/).
So both (clamav-milter and postfix) need access to that file and therefore it has to be inside of the postfix spool directory, otherwise it will not work with the Unix Socket option.
Ok thanks. Tested and is working fine. I'll release the new version in a few minutes..
Version 1.1.5 has been released in plugin store. Version compatible with i-MSCP >= 1.2.3. Big thanks to @mrpink!
CHANGELOG
Yes, default values are now Unix Socket.
No, you could update directly.