Preseeding Postfix for No configuration

[Erik <erik@vanlinsteeict.nl>]

Hi,

I am not sure where to go with this. It relates to postfix, but is not a 
problem
with postfix itself.

May one of you can help me along.

I am doing an unattended install of Debian Buster with postfix being
added using apt-install in the preseed/late_command.

Without a postfix preseed definition in my preeseed file, I get the expected
question about what kind of mail configuration I would like.
When I select "No configuration", installation continues as expected and I
end up with a postfix installation without main.cf and without master.cf.

But when I preseed postfix with "d-i postfix/main_mailer_type select No 
configuration"
as both debconf-get-selections and 
https://preseed.debian.net/debian-preseed/buster/amd64-main-full.txt
confirm I should do, I get an extra question asking me about the system 
mail name.
Clearly, this question is out of place for a "No configuration" install.
And as a result I end up with a main.cf and a master.cf, which contradicts
the "No configuration".

So something is going wrong. Apparently the preseeded selection for
configuration type is accepted, as that question is not asked, but it
is not interpreted as "No configuration".

Any suggestions as to what I might be doing wrong, or where
to better ask my question if this is not the right place?

regards,
Erik