Mocking up a battery tray before fabrication

I am working on a battery tray and would like to catch fit problems early. What do you check during a cardboard mock-up?

Access for installation and removal. A tray can fit perfectly while leaving no practical way to get the battery into it.

Leave room in the mock-up for the connections and the parts that surround the tray, rather than checking only the battery case.

I write down each clearance I still need to verify. The template is a planning aid, not proof that the final mounting arrangement is ready.