Sorry, I don't mean to hijack this reply, however I follow the steps, the port 8081 does appear after reload the firewall and restarting mgmt service.
However there is an error while connecting via <IP ADDR>:8081 via the vsphere client
"Call "ServiceInstance.RetrieveContent" for object "ServiceInstance" on Server failed." .. any ideas?
Proxy.xml
<ConfigRoot>
<httpPort>8081</httpPort>
<EndpointList>
...
..
Services.xml
<service id='0017'>
<id>vSphereClient</id>
<rule id='0000'>
<direction>inbound</direction>
<protocol>tcp</protocol>
<porttype>dst</porttype>
<port>902</port>
</rule>
<rule id='0001'>
<direction>inbound</direction>
<protocol>tcp</protocol>
<porttype>dst</porttype>
<port>443</port>
</rule>
<rule id='0002'>
<direction>inbound</direction>
<protocol>tcp</protocol>
<porttype>dst</porttype>
<port>8081</port>
</rule>
<enabled>true</enabled>
<required>false</required>
VpxClient.exe.config
<add key = "protocolports" value = "https:443;http:8081"/>