Has anyone tried to upgrade the beast's ABS ? Is it possible to install the C-ABS functionality to the SD ?

Comrade: Haven't done this but I'd imagine you'd have to change the ABS ECU software at least to that used in an Adventure. It's worth a try but it could be a downward spiral in that you may then also need to update the software in the other ECU's as well.

If it can be done on the ADV it can be done on the 1290SDR as the hardware is pretty much the same.
Don't know why KTM hasn't released a pay for update yet as they did on the ADV.

Anyway as Jmann pretty much stated I wouldn't go there unless it is approved by KTM.
Several other ecu's software on the bike need likely updating too as it relies on the G sensors and countless other things to do it's job.
Only a dealer can do it anyway as a diagnostic tool is needed to load the software, and I'm petty sure they decline unless green light by KTM!

Add in TC and now you really are taking away the fun and skill factor of riding a bike

I'm not a fan of rider aids. I can see them being great if you ride all through our shitty winter but other than I want to rely on my skills of controlling my bike. Modern bikes/tyres are amazing, the way things are going with cars they will be drive-by-wire before we know it with the machine only applying your inputs if it agrees.

Maybe it will come as a dongle or something.

I used to agree with Colonel regarding the aids but that was before the beast. I find its ABS really close to perfect and its traction quite useful with so much torque, specially in slipery greek wet/dry roads.