I have read a few of the topics where it's stated there was a possibility to somehow route via TC Near mixer to access more than the 2 analog main Ins or Outs with the Konnekt 24D slaved via Adat to another Interface.
I am using a Focusrite Clarett 8 Pre [ Master ] & [24D Slave ] via optical ADAT
This setup is stable & happily providing me with it's 2x2 analog input/outs which is very nice 
Would be interested to see if anyone has been successful in accessing input/outputs 3 & 4 in this situation?
Also is this possible with the Impact Twin?
Cheers