There seems to be some confusion here (which I'll probably add to).
I think that above you've compared what SP call the 2as and AT831s.
The specs for the CMC2s are different:
Brand SOUND PROFESSIONALS
Description DELUXE AUDIO TECHNICA CARDIOID STEREO MICROPHONES SHOWN WITH CLIP OPTION - TEMPORARILY UNAVAILABLE
Price $139.00
Reviews Number of Reviews: 7
Avg Score (out of 5): 4.9
More Info/Add to Cart View
Specifications Frequency Response 40-20,000 Hz
Signal To Noise Ratio 65dB
Open Circuit Sensitivity -42dB
Maximum Input Sound Level 116dB/131dB/141dB
Dynamic Range 87dB/102dB/112dB
Polar Pattern Cardioid
Dimensions .4 X .98
Cable Length 48"
Microphone Body Material Painted brass
Features Interchangeable capsules available? No
Windscreens Premium small
Croakie Option Yes
Clip availability Optional standard rotating clips or stationary lapel clips
And they look very different to my CMC2s. To be honest I've no idea what capsules the 2As are based on, anyone?
The 'out of stock' time I stated above of 4-5 weeks was for the CMC4s - it seems all AT mics are out of stock right now.
You asked what SP do to the mics? As far as I'm aware:
-Shorten the leads to 4 ft or so
-Terminate them in a 1/8" mini
Thats about it I think.