It's setup in a similar way to the vWLC, unsurprisingly, but there's a couple of little quirks because I'm using an older controller that I've picked up and I want to record them.
1) Factory installed certificate expired. The factory installed certificate on the controller expires, stopping APs from joining to the controller.
There's a command to override this, but it didn't seem to work for me, so the easy fix is to turn the WLC clock back a few years. Obviously not a production fix but for my initial labbing, no issues.
2) Management Interface vs. AP Manager
I assumed, wrongly that the AP manager was the IP address to use in the DHCP option 43, however, that's not the case, it's the management interface just like the vWLC. But, worth noting, you still need the AP manager interface on these older controllers, and it must be reachable for the APs. Seemingly it manages DTLS connections between the AP and the WLC. When I removed the AP manager VLAN, thus making the AP manager address unreachable, the APs would cycle through the DTLS connections timing out and then retrying. Once the AP manager VLAN was re-added, the AP connects and registers with the controller.