With the gear that you mentioned, you could run:
mics>UA-5>JB3 (optical)
+
SBD>HDP2 (analog)
(or vice-versa SBD>UA-5>JB3 + mics>HDP2)
And then use the digi coax output of the UA-5 to feed the coax input of the HDP2 (you have to set the clock source of HDP2 to coax). So the clock source would be coming from the UA-5. The UA-5 only puts out 24bit, so no worries there. Both opti and coax outputs on UA-5 are hot at the same time.
Or, if you'd rather run an on-the-fly mix, then run:
mics>UA-5(xlr)
+
SBD>UA-5(rca)
>HDP2(coax)
Personally, I'd go the first option. Much more flexibility.
Run each rig individually, then sync em up in post. Since they are on the same clock source, syncing up is easy.
Hi-Z should be off.
ADV is for 24/96 recording only.