...but it did in Server 2012...
So, I bided my time and waited...and waited...for Broadcom to get around to releasing a version of BACS and driver software that actually works on Windows Server 2012 R2... Installed the driver update (16.2.0.4) and the updated version of BACS (16.3.4.0). NIC ports are detected fine and work individually. BACS launches and doesn't crash immediately. Yay! (or so I thought)
I attempted to create a LACP team using the two ports on the onboard. On the switch (a Cisco SG200-50 switch, running the latest available firmware version) I configured a LAG, added the correct ports, enabled LACP. The virtual team interface on the server, however, while advertising that it is up and running (confirmed in the switch UI), will not get an address and returns the dreaded "unidentified network" status in control panel. I've tried creating the team before and after having the LAG configured. I've even tried every possible combination of team type and LACP enabled/disabled without avail. The thing simply doesn't work.
I have a 4-port Intel I350-T (latest driver version from Dell) adapter installed in the machine. Using the Intel ProSet teaming utility, configuring an LACP-enabled team with a correctly configured LAG for all 4 ports works without issue.
Sadly, any logs I reference are less than helpful revolving almost exclusively around the fact that the adapter cannot get a DHCP address when initially configured.
Any ideas on this are greatly appreciated.