can u change some script so it will not delete all configs made by hand?
i changed dovecot.conf to disable all unencrypted logins, enabled managesieve, change some process limits and more. everthing gone after upgrade! 
maybe u can change your script to if_exist . dovecot.conf.local or something.
my upgrade error when upgrade to 1.2.0:
Servers::httpd::apache_php_fpm::disableConfs: Configuration file other-vhosts-access-log.conf doesn't exist
comes from the directory conf-available, this was made from a icinga2 install. simply delete the directory and it works in 1.2.0 also.
thank your verry much!
We will not do that. Search on the forum to know why.