It seems one is allowed to post custom made SDRsharp versions. At least if one includes the (modified) source code. So I will give it a try:
Things are based on one of the older SDRsharp version, somewhere around end 2012, maybe some of the later Plugins might not be compatible.

Short list of modifications:

- Support for ExtIO based SDR radios like Perseus, PappRadio (tested) and others
- Audio FFT (Audiogram) with switchable audio samplerate
- 'S-meter' indicating S-points, dBm or dBuV and Eibi StationList
- Keyboard support and shortcuts.
- Independent Spectrum, Waterfall and Audiogram speeds.
- Baseband display with a max of 4 configurable notches.(no audio notch !!)
- (vector)Scope display with AM modulation level metering.
- Floor, Span, Intensity and contrast sliders.
- Perseus style screen layout (skin).
- And some more minor things

Maybe however you do not like the above, then please forget all this. :-)

To install the stuff, read and use the procedure as described by gubo68 in the ReadMe.txt document in his SDRSharp_gubo68_4d.zip file.
(see files section).