First turn on after swap

 Following the EVs Enhanced instructions I inserted the HV Disconnect plug, then reconnected the 12 V battery and turned the car on.

It just worked. The latest Translator Kit even takes care of the battery pairing process. 

The Keyfob Miss Registration error message is old.

So then I plugged the car in for a charge and:

That's up from 102 km Estimated Range from the old battery.

My own (not so giddily optimistic) range estimator tool says 111 km, up form 70 km.

So I'm looking at 40 km extra range (+33%) for a NZ$2800 battery.

I'm happy with that.