A while back a guy reported that you could alternate model match numbers with the DX4e module and thus control 2 receivers.
I could never get it to work though so he might have been full of
Post is here:
Had I got it to work I would have put it forward to be included in ER9X to get around the 6 channel limit.
When I tried it neither receiver worked, but I had genuine Spek, he said he was using Orange.