I recognize when I go work from a coffee shop that I am using their resources.You should also recognize that you're using the resource (rivalrous) of other patrons.
they'd not only lose my business, but that of friends when I tell them about the experience.
Nothing personal, but if what you're telling them is that it's a good shop because they let you hang out all the time while buying little (less than their normal sit-down turnover proportion), then it's probably better that all of you stay away. I mean, your friends probably aren't idiots and they know you're not recommending the shop because you can't stop drinking their coffee and eating their food.
What would benefit the shop the most is if you were going broke from spending so much money there, and I'm gonna guess that's not the message you're sending. Your tone is really more of the (prospective) freelance client who says the gig is going to be "good for your portfolio," so can you work for cheap this time?
Again, I don't know you so this can't be personal, and you very well may only be there for an hour a day. It would be interesting to see proponents of coffee-camping and their $/hr spend at the places they set up shop.