Poli definitely did a lot of designs. I still haven't ascertained whether he executed any pieces himself and we may never know if he did. I have to agree that some pieces are definitely lack lustre, but I still enjoy seeing them anyway.
Ivo, there is piece in design and arts shop that has a label - 50666. Another without a label. I have only seen that label on two pieces of glass, both optic pieces from SVdA. Unfortunately I didn't snap up the other piece and i no longer have the listing for it as it was some time ago.
Hopefully a piece will show up in the near future with the standard SVdA label and put the matter to rest. My opinion still is, that this is a Poli piece. The feel, the look and the 2 layers of blue i believe is his work.