As promised did I do some test with this polar function.
First I decoded some audio with the normal CCIR stereo. My Polish tuner seemed to work rather well with this regular stereo.
After this I changed to polar stereo and unfortunately I discovered that my tuner doesn't support polar stereo.
I did also make a video of the spectrum with sdrsharp.
https://youtu.be/IC35nR6Xh8w
So for me does the polar seem to work rather good although I don't have the possibility to decode the Polar stereo.
So it would be really great if there was somebody that could write a polar plugin for Sdrsharp.
This video I made last year with a sporadic E skip. As you can see there are many stations on-air with stereo. Those stations all have to be in CCIR 19 KHz stereo.
https://youtu.be/ByTGEtckfM4
https://youtu.be/YTI6KWyHT2w (many stations are in mono or Polar)
If I will somehow find a possibility to decode the polar stereo I will post it here.