think of it this way...
if the a>d converter section is turned on every output on the V3 is active.
The analog outs , the coax out and the xlr aes out. You can use them all or in any combination.
I'm just spitballing here but with the addition of a aes>s/pdif converter you could run four channels off the same clock
run mics> v3> aes to s/pdif> MT
run the spdif output on the V3 to 702 and sync clock to s/pdif
run 2 more channels into 702 (sbd patch or whatever)