As per the title, the option 'disable' does not work for mutually exclusive options. The checkbox for activesync is not disabled when the checkbox for lite is checked.
[option "kolab"]
accounttype = individual,group,group-member
ldap_role = "cn=kolab-user,$root_dn"
implicit = true
price = 9
setup_price = {monthly=50, annual=0}
[option "activesync"]
accounttype = individual,group,group-member
description = signup.activesync.description
ldap_role = "cn=activesync-user,$root_dn"
price = 1
[option "lite"]
accounttype = individual,group,group-member
description = signup.lite.description
ldap_role = "cn=imap-user,$root_dn"
disable = activesync,kolab
price = -5