The KDE SMB IO handler (kio_smb IO slave) is, AFAIK, using the libsmbclient library.
So my guess is that it should behave like other Samba clients using the same library.
If you need detailed technical information you might get it on the kfm-devel mailinglist, the Konqueror developer mailinglist, however, as it is a developer mailinglist, a posting there should bring this need across, because sometimes user questions end up on such mailinglists and developers get frustrated and ignore any posting looking like one.
Cheers,
_