The service file of the current Netatalk is not appropriate because it use
a shell-script "netatalk.sh".
Two experimental files are for future netatalk.

These files start daemons directly and do not read "netatalk.conf".
Therefore, you need to edit files for setting options.

ATALK_NAME:       set in afpd.conf instead
AFPD_MAX_CLIENTS: set in netatalk-afpd.service by using -c
AFPD_UAMLIST:     set in afpd.conf instead
AFPD_GUEST:       set in afpd.conf instead
CNID_CONFIG:      set in netatalk-cnid_metad.service by using -l and -f options

There are no service files for atalkd, papd, timelord and a2boot
because AppleTalk feature is due to be abolished in the future.