You have not described your porch, but porches and decks are often basically the same. And not all jurisdictions require a permit to build a deck; it depends on size and the local rules.
I built a 10 x 20 deck off my kitchen; the opening to the deck is a 2 pane sliding door about 6 feet wide.
Attached to that to the left, and one step up was a another deck approximately 12 x 13; and to the right one step down was one that was about 8 x 12.
I remodeled the house when I was going to sell, and the city inspectors (there were two) came out to look at the remodel.
They had one issue with the plumbing in one bathroom (easily fixed) and complimented me on the remodel and the deck.
I never got that permitted when I first built it, nor when I tore it down to the stringers and built it back up.
A non-issue.
You have not “cheated” the local government. They want to know if there are encroachments on any setbacks, and that it is properly constructed. There might possibly be a fee, but in the scope of things, it is very minor. It is not a moral issue; it is possibly (and not likely) a legal issue (code).
If it is going to stick in your craw, then have someone else ask the building department a theoretical question and find out what the rules are; I suspect that you will find it is pretty much a non-issue.
Not all appraisers are totally code savvy, but the house appraised (and presumably you had a full home inspection by a licensed contractor prior to closing, as part of your offer). If neither of them found anything flaring, odds are strongly it is fine.