All good points, however new construction and remodeling are somewhat different. Even a custom home and a home being built in a development can be different right? Isn't there something about ownership of the house in a development is with the builder until the homeowner closes on the house? Remodelling someone's kitchen is a bit different I think. Also we aren't talking about something that can be stored in a box.
The example I was thinking of my 20-foot decking, lots of it, way too much to be moving around multiple times. It doesn't fit in a box, and the homeowner isn't going to pay for a huge storage bin. It gets dropped by a truck and that is where it sits.
I'm thinking about a situation where you can't put the stuff into a safe place such as the homeowner’s garage or back yard, hell even if you could I think I will still have them sign for responsibility. I might say something like:"Here are the materials for the job, they are here now and I just need to let you know that I need you sign this form that just says that the materials are now on your property and that if anything should happen to them it is clear that you are responsible for them now, if someone breaks in or if the house burns down, the materials are considered delivered."
This could be $5000 worth of deck lumber or $10,000 worth of cabinetry waiting to be installed in their kitchen.