Sorry, can't help with your question.
Have you considered and researched replacement? Have you tried cleaning up any corrosion on the board?
"qualityporscheparts" has several sets for $450 and they'd probably accept $400. I have no idea what's involved or how easy it is, but I think several here have done it. I can vouch for "qualityporscheparts". Very reputable folks.
I believe that if you replace the immobilizer and ECU as a set and buy the correct year/model (as in the ad below) that no dealer coding would be necessary, but I have not researched it. Search for "Porsche 986 Boxster immobilizer replacement". There are other components that contain the VIN that must be considered, like the gauge cluster and climate control, but I don't think that a match there is absolutely essential since people swap clusters an CC units on occasion.
Research it whilst eating a nice twice baked potato.
00 Boxster s rwd Porsche 986 Immobiliser Set Engine Computer Key Ignition 55 351 | eBay
You wouldn't actually need the locks, just the immobilizer, ECU and key head (internals - transponder pill and keyless entry transmitter board).