X-Kannel-SMSC and message splitting

Hello All,

Just a question really. I've been looking at the X-Kannel headers and
noted that if you receive an MO message from SMSC 'A' and you specify
the message should go back via SMSC 'A' for normal short message fine. 
However if you respond with content with content that gets split. The
first fragment goes through the correct SMSC ('A') but the other
fragments get sent in normal load-balancing fashion. 

Should all content go through the specified SMSC or is the current
implementation by design?

Cheers,
Alan