Here is the W & B notes from the OzRunways web site:
Guess this is an area of the regulations that needs to be updated to take advantage of modern technology.
Is Weight and Balance Approved? / Frequently Asked Questions / Knowledge Base - OzRunways Support
Is Weight and Balance Approved?
Weight and balance does not require specific CASA approval. However, if you want to use the weight and balance feature in OzRunways as primary means of calculating weight and balance, your configuration needs to be validated and approved in writing by a CASA approved weight authority. This generally means a CAR 35 approved engineering firm.
Simply copying the numbers from the POH does not make it legal.