It's a while since setting up a 302 and I don't have one to connect to, but in the CAI utility software for PC or IPAQ the "sink tone on" checkbox is for climb mode. The "speed up" tone is always on.
This was the opposite of the SN10 software when I owned one of those just prior to my first 302. You couldn't turn off the SN10 sink tone in climb mode, but could turn off the "speed up" tone.
The polar just comes out of the glider manual. If it doesn't agree with real life change the numbers. Lowering the 2m/s speed helps make it realistic.
Check that the configuration is not locked on the "Edit Glider ID and Polar" page, otherwise all you can change to fix it will be bugs.
Jim