I'am not the moderator that reviewed the flag, but as stated by ward in comment it's in the reopen review, and it's still there today.

As seen today:

[![enter image description here][1]][1]


  [1]: https://i.sstatic.net/8nf4v.png


The voting still follow its course, but personnally I would had voted to migrate to SuperUser, but close on SF. The reason behind my logic is that you don't control machineA router and it seem to me you want to bypass asking the firewall admin to make exception for your case. The legitimacy is lost there on my side, and all the question complexity come from that fact.

To make it clear, that make me think in example; what would happen if you install such bypass in a HIPAA's setup? Can you get fired to have not asked the network admin to do what you want to do?

It's the reason on my side that I wait for the community to decide for the reopenning. Your question is really well worded and with a lot of details, so it show your effort into your question and I really apprecitate that. I maybe miss a detail that make it more fit on ServerFault, but in doubth I prefer not to intervene. If it stay closed I can ask SU's moderator if your question could better fit there without problem. 

*Edit: I asked SU's mod, and yes it could fit there but the fact you don't control the network gear will problably bug them too.*