It is possible that the Launchpad user may not be subscribed to all the packages one is interested in, in which case you may want to see packages for the user and another package. However, this seems like a rare situation to me and not being able to specify both at the same time would work for most cases.
It is possible that the Launchpad user may not be subscribed to all the packages one is interested in, in which case you may want to see packages for the user and another package. However, this seems like a rare situation to me and not being able to specify both at the same time would work for most cases.