Some more information: I ended up doing some more troubleshooting with wireshark and discovered that I AM getting TCP connections from the iPad and the windows machine when setting the the Unicast Endpoint to 0.0.0.0, and I get some packets when hitting connect.
1.) I hit connect. I see a TCP packet being sent from the iPad to the windows box, inc port 49566, destination port 2049:
138 4.770959 192.168.1.70 192.168.1.10 TCP 78 49566 → 2049 [SYN] Seq=0 Win=65535 Len=0 MSS=1460 WS=64 TSval=1058697453 TSecr=0 SACK_PERM=1
2.) The windows box responds with a TCP RST ACK packet, source 2049 to 49566:
139 4.771003 192.168.1.10 192.168.1.70 TCP 54 2049 → 49566 [RST, ACK] Seq=1 Ack=1 Win=0 Len=0
After that nothing. Connection refused. So at least the conversation starts, but it looks like after the ACK, it’s shutdown.