Branched radials are fine as long as the cable is appropriately matched to the protective device and i'm sure they get installed from time to time where physically circumstances dictate.
Junction boxes are frowned upon in new wiring for a couple of reasons reasons. Firstly every connection is a potential point of failure so the less of them the better. Secondly electrical connections are supposed to be accessible for inspection (with some exceptions) and junction boxes have a tendency of ending up inaccessible (even if they were accessible at the time they were installed).
Junction boxes are frowned upon in new wiring for a couple of reasons reasons. Firstly every connection is a potential point of failure so the less of them the better. Secondly electrical connections are supposed to be accessible for inspection (with some exceptions) and junction boxes have a tendency of ending up inaccessible (even if they were accessible at the time they were installed).