I just posted my preliminary BCR2000 preset for the 3P Upgrade in the Files section.
It's not completely tested yet, but I'll announce new updates here.

You'll have to use the BC Manager ( http://home.kpn.nl/f2hmjvandenberg281/bcman.html ) to import the file, so you can incorporate it in your existing BCR presets. If you have any questions how to do that, please ask! The BC Manager is a must if you have a BCR/BCF, it's endlessly better than the stock software you get with the BCR/BCF, and it's free (although you can donate to the author).

I haven't gotten round to creating a visual map of where all parameters are located, but you can do that quite easily from within the BC Manager itself.

The preset assumes you have the 3P at MIDI channel 12. If yours is set differently, change it in the BC Manager before sending the preset to your BCR:
0. Go to the Presets window
1. Choose the preset "Roland JX-3P (Kiwi)"
2. Click the button "Show Buttons" - the "Buttons" window opens
3. Press CTRL-A to select all parameters
4. from the menu, choose "Edit\Set\Channel" and select the desired channel
5. Close the Buttons window
6. Again from the Presets window, click the button "Show Encoders" - the "Encoders" window opens
7. Repeat 3 and 4
8. Close the Encoders window

If you find any bugs or have suggestions, please reply to this thread!