all depends on what resources you have available at what price.

ideally you would want it done on an engine dyno first as in theory you can do all of the part load stuff and warm up stuff and whatever, quicker than in the car.

you would then need to tweak it all once it's in the car with proper exhaust and inlet and airflow though.

the chassis dyno could also be used for certain parameters where airflow is not an issue, but is basically a waste of time compared to in car live map which you should be doing anyway.