Panorama X gives you the option of whether you want it to append all records or just selected records.
Summary records are intended to be extremely transient, not something to save and transfer around from database to database. If you need them, you regenerate them, then remove them again.
In the past, some users have used summary records to essentially store an extra bit of data in each record. I've been trying to discourage that for a long time, and Panorama X goes even further in that direction. That sort of usage of summary records is not supported. You should never manually create or uncreate summary records -- they should only be created by the Group commands or Summary dialog, then removed when you're done. If you need an extra bit of data, add another field.
Well, that's a possible feature to consider on it's own. For now, you can do this with a short procedure.
let data = arrayselectedbuild(cr(),"", exportline())
This won't preserve summary records, though, they will come in as data records.