Use of enable: True on FreeBSD is a drift from our standard practice

When run on FreeBSD, the service state module will call the freebsdservice execution module.

Salt documentation in execution module freebsdservice states for freebsdservice.enable:

config/etc/rc.conf (read probably config)
Config file for managing service. If config value is empty string, then /etc/rc.conf.d/<service> used. See man rc.conf(5) for details.
Also service.config variable can be used to change default.

So that's documented to create - correctly - /etc/rc.conf.d/dovecot and write dovecot_enable="YES" there.

Everywhere else in the rOPS code, we manually create that file. The only value added to the manual operation is when we need to customize other values than only _enable. As long as it's not the case for Dovecot, the use of enable is perhaps A LOT simpler than file.managed + a new template.