here's a link to the technical bulletin re the chain change, when it happened, and what parts changed:
http://www.pelicanparts.com/techarticles/Boxster_Tech/16-ENGINE-Camshaft_Swap_and_Chain_Tensioner/Gp1800.pdf
the tensioner changed with the chain change, but the paddle didn't. is the updated tensioner ok to use with an old chain? no idea. the tsb says "a mixed configuration is not permissible, as the parts are matched with each other."
a review of part #'s shows:
TSB part number of original roller chain tensioner (ie, as of August 2000): 996 105 180 54
current PET part number for roller chain tensioner: 996 105 180 57
superseded by PET part number for updated roller chain tensioner (presume after the chain change or would have been noted in tsb): 996 105 180 59
PET part number updated toothed chain tensioner: 996 105 180 56
why would they update the roller chain tensioner after the fact if the toothed chain tensioner was up to the task?