This Mikrotik device has a third port, a 1000Base-T one. That should be plenty for BMC.
I am thinking of using this. But it seems like overkill, and I am not interested in learning RouterOS.
RouterOS can be managed using a GUI, with an app called Winbox. It is windows application, but runs fine under wine, arm macs included. You still need to know the concepts, but in a nice clicky way.
This Mikrotik device has a third port, a 1000Base-T one. That should be plenty for BMC.