There are a couple filters in the previous .csv file corrupted with extra double quotes. All or most are fixed in the attached file here.
To get ISPConfig 3 to write the /etc/postfix/*_checks files you first have to erase or rename the existing ones, then thru the ISPConfig interface you need to change and save a filter. Deactivate one, save, activate it again, save... works.
With the above filters and the below added to /etc/postfix/main.cf I am getting no spam. Between 600 to 1000 a day rejected. All non-spam seems to be getting through ok.
# Some spam blocking measures
disable_vrfy_command = yes
smtpd_delay_reject = yes
smtpd_helo_required = yes