[Scribus] import scalable... anything... into Scribus ?

[stu seven]

+    I know, in principle, Scribus allows SVGs to be imported...
for me, this seems to work only with very small SVGs.

     Scribus also seems to optimize it's PDF output... which
should be good... except that, when I put a PDF-d image in
the scribus document, it ruins it... re-optimizes it... sort of
like drinking your soda twice(?).

     So here is my question... is anyone having success
including SVGs, or, other scalable format files in scribus
documents ?

note:  Ive had fairly good results with plain bmp or jpeg graphics...
however, this falls apart when the resulting PDF is enlarged at all.

thanks for looking