It isn't on the SME website yet, but you'll find it listed with some UK dealers: a version of the Model 12 with room for two tonearms:
https://www.analogueseduction.net/turntables/SME12atwin.html
It looks like SME have copied what one of their more adventurous dealers did a few years back for the Model 10:
http://www.time-step.com/distribution/SME%20Dual%20Arm.html
I asked and they said the subframe is different on the 12 and it won't work on my 10s. But they would say that, wouldn't they? All it would take would be a replacement for the mounting plate, A, with a dogleg protruding out from point B, at 120º to the axis of the existing plate, into which a second SME mount is machined.
The annoying thing is that it would take five minutes in their CAD app to change the mounting plate for the Model 12, and then they send that, on demand, to their CNC machine when they want to sell one to a Model 10 owner. Easy money, but they prefer to hope I will buy two Model 12 Twin tables to replace my two Model 10s with their Acoustand pods. That's not going to happen!