Yes, they can source if it's not on display. If I find something on the H website that the store doesn't have on display, I usually just pull it up on my phone and he puts the reference number in his phone and tells me what the availability is. If it's available at another store, then they can do a charge send and ship it to your home directly or ship it to the store. If it's only available online, and you are physically in the store, then they can do a "click to pay" and order it from the web store. They can only do this if you are physically in the store. (Weird I know, but that's how it is.) Sometimes when I check out, I have stuff from the store, stuff that's coming from another store, and stuff that's click to pay from website, and stuff I am taking with me and other stuff that they will ship to my house.
I've always had a great experience at Madison. Even random SA's that I share the elevator with have been helpful and nice, compliment my outfit or my bag. And every floor there is a host/hostess who will ask you what beverage you would like. My favorite is the 4th floor though.

And I always ask for extra cookies to bring home lol.