And, at the ones where the food vending is on the inside, it's on the "paid" side of the cash registers. You can get to this area just by claiming you're "going to member services", since that's also on that side, and it's where you go when you forget your card (and so can't show membership at the checkpoint).
Source: Have forgotten my card a lot.
I've never seen a Costco with the food vending in a window on the outside of the building. I've always seen it against the wall after the checkout. Which is also after the checkpoint.
I think a window on the outside of the building only works in moderate climates. I don't see it working in Phoenix or Minneapolis.
The food court I'm not as sure about, but in both cases I've walked into a Costco with no membership and they were fine with it.
[0]https://www.costco.com/Costco-Cash-Card.product.10024438.htm... [1]https://www.google.com/maps/place/Costco+Wholesale/@37.25296...
I've heard this touted as a "hack" but this makes absolute economic sense for Costco -- they get an advance on your purchase and get you into the store to potentially see the value in signing up.
I just didn't imagine they'd let me say "Um, yeah, put $1 on my Costco Cash card, and the other $399 on my Visa".
Thus, while it is possible, their devout employees don't like it and go out of their way to make one feel like a leper for not being a member.