It would be good to have an option in the combination channels to grab only the logo.
In the case of grabbing from tvguide, the channel logos are not grabbed. I achieved a similar result using this, but maybe it could cause some weird issues.
{channel period="00:00-00:01" update="i" site="tvpassport.com" site_id="tvpassportsite" xmltv_id="12"}CBS{/channel}
{channel period="00:00-24:00" update="i" site="tvguide.com" site_id="tvguidesite" xmltv_id="12"}CBS{/channel}
(Note: replaced gt,lt symbols with brackets {})
Additionally/alternatively for the include and exclude options it would be nice if a wildcard could be accepted.