Yes, Matthew 11:19, Luke 5:29-32, and other verses record such events. We can safely infer from Scripture that Jesus interacted with sinners but in no way endorsed nor partook of the sin.
To the hypothetical situation, I would agree with the author that Jesus would have sold cakes to the gays as normal interaction with sinners but would not have baked a wedding cake which would have been seen as an endorsement of the sin. Of course, that is just speculation but I don't think that it is a real stretch.
>> “Isn’t there something in the Bible about people giving Him a hard time for eating with the heathens and other lowlifes, as they saw them?” <<
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That was specifically the day he recruited Matthew, a Cohen by birth, but a toll taker for the Roman Gov’t.
He was the first author of a New Testament book.
But Yeshua didn’t in any way endorse Matthew’s old life. He didn’t make him the head of his Publican Division.
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