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The sentence with "frequented" is awkward, or unnatural, but the other two are fine.
"Well-patronized" is more natural than "very patronized." A natural phrase or adverb to intensify "frequented" doesn't come to mind. We usually use "frequented" when mentioning a certain clientele or type of people or others which may be found at a given location. "The street was frequented by prostitutes." "The restaurant was frequented by movie stars." "The park was frequented by pigeons."
Don't forget to place periods at the ends of your sentences.
- A.