I have customised the files as described in the readme [1], created a custom site, changed the update path, the version number and the sogo-connector.autocomplete.server.urlid (lpref("sogo-connector.autocomplete.server.urlid", "ldap.example.com")) and built the xpi.

Installation works, after restarting Thunderbird there's a prompt for user name and password and then calendars and address books are syncing.

The problem is Thunderbird creates the same ldap address book after every restart as a new one, so there are multiple entries when looking at about:config like this:

ldap_2.servers.public.uri
ldap_2.servers.public_1.uri
ldap_2.servers.public_2.uri
ldap_2.servers.public_3.uri

site.js (we only changed this one line)

pref("sogo-connector.autocomplete.server.urlid", "ldap.example.com");

sogo.conf

SOGoUserSources = (
{
CNFieldName = gecos;
IDFieldName = uid;
KindFieldName = kind;
MultipleBookingsFieldName = Multiplebookings;
UIDFieldName = uid;
baseDN = "ou=Users,o=example,c=com";
bindFields = (
uid
);
canAuthenticate = YES;
displayName = "Example Users";
filter = "(status='A')";
hostname = localhost;
id = ldap.example.com;
isAddressBook = YES;
port = 389;
scope = ONE;
}
);

prefs.js after sogo-connector installation in Thunderbird:

user_pref("ldap_2.autoComplete.directoryServer", "ldap_2.servers.public");
user_pref("ldap_2.servers.public.description", "Example Users");
user_pref("ldap_2.servers.public.filename", "ldap.mab");
user_pref("ldap_2.servers.public.uri", "carddavs://sogo.example.com/SOGo/dav/testuser/Contacts/ldap.example.com/");

prefs.js after the next restart:

user_pref("ldap_2.autoComplete.directoryServer", "ldap_2.servers.public_1");
user_pref("ldap_2.servers.public.description", "Example Users");
user_pref("ldap_2.servers.public.filename", "ldap.mab");
user_pref("ldap_2.servers.public.uri", "carddavs://sogo.example.com/SOGo/dav/testuser/Contacts/ldap.example.com/");
user_pref("ldap_2.servers.public_1.description", "Example Users");
user_pref("ldap_2.servers.public_1.filename", "ldap-1.mab");
user_pref("ldap_2.servers.public_1.uri", "carddavs://sogo.example.com/SOGo/dav/testuser/Contacts/ldap.example.com/");

after every Thunderbird restart, a new directory server is being added like "_1", "_2" and so on. It also creates a new MAB file every time. Thunderbird automatically uses the newest one in

"ldap_2.autoComplete.directoryServer" every time. The Preferences > Composition > Addressing menu always only shows one directory server, not multiple (see attached screenshot from the 5th Thunderbird restart).

[1] https://github.com/inverse-inc/sogo-connector