Well yes and no. First to run DANTE enabled software, you need at least Dante Via on one of the PC’s for the clock source. Also this can give you 16 channels of input in ASIO (Windows) or CORE Audio (Mac) mode. If this is enough for the live stream, use DANTE Via on that PC. To use your setup, it will have a very large round trip latency (at least 10mS from DANTE Via, at least a few mS for the USB connection (out AND in) and Virtual Sound Card will also introduce a few mS latency). Why do you want to use the card slot on the SQ for a second S Link port? If DANTE is something you want to use, take the DANTE option card, run DVS on the PC’s and you are pretty good to go. SR Performer will only be useable for the FOH mix, not the monitor mix in this case, because DVS adds too much latency to use with IEM.
What you also can do, is add the Waves option card, buy 2 good refurbished mini pc’s (HP Elitedesk G4 mini with a 9600 chip for example) and make one of them a Waves server and use the other for Super Rack SG. Then you can use another PC for the live stream mix with Waves QRec (Waves version of a Virtual Soundcard).
Maybe a bit more expensive, but very little latency for Super Rack, so also usable for IEM mixes and not (very) limited to also send all channels to the live stream pc.