The introduction of native systemd units in 1.13.1+dfsg-1.1 made one
specific issue with dictd much more visible: all dictd providers have
a postinst containing (some variation of):

         invoke-rc.d dictd restart

This works, but as by default, systemd doesn't like burst restarts, it
imposed the addition (in 1.13.1+dfsg-1.2) of the StartLimitIntervalSec=0
systemd unit configuration, which has other consequences.

The correct and modern way is to have dictd register a dpkg trigger, and
all providers of dictionaries to trigger it; then dictd does a final
restart after all installations/upgrades. It would need quite some
coordination to update all dictionary providers, but if done correctly,
it would mostly mean that all they have to do is "just" remove their
postinst.

Sadly, I don't really have capacity to help with this.

Best,
OdyX