Way to show resourcefulness Neil. We owe you an apology.
The reason why you did not get a response is because Centrify does not actively test that Linux distribution. Although it is a Debian derivative and with some curiosity you can make it work with our client, there will be unexpected behaviors.
If you think Lubuntu is gaining ground (plus there's the possibility for Enterprise-type customers to start using it) we encourage you to use the Idea Exchange.
For information about supported platforms, check this out: https://www.centrify.com/products/server-suite/system-catalog/
R.P