New configuration syntax: how to disable services?

There have been quite a lot of configuration changes recently, and to get rid of startup messages like

“Config warning: Option “**********” is recognized but obsolete, and will be removed in a future release.”

I’ve now tried to move to the new syntax. I started with kopano-ical, and found either a problem or something is unclear to me.
Previously I was able to disable ical over http (port 8080) easily

# whether normal connections can be made to the ical server
ical_enable = no

How does disabling a service, like for example unencrypted IMAP or unencrypted ICAL work in the new configuration syntax?
I was expecting to set

ical_listen = 

to an empty value to prevent it to listen on any interface. But this does not work: Server is still listening on Port 8080.
I could use “ical_listen =” or a firewall rule to prevent outside access, but shouldn’t there be a way to actually disable a service like in the old days with “ical_enable = no” ?

All I can say is, you are right, and then (!!curses at the old config directives!!)