One again we're getting into the distinction between "w/permits" vs "permissible". Which sometimes they mean similarly in the market but sometimes they don't.
As a hypothetical, if a jurisdiction is effectively allowing a use to continue and the market is seeing that, their expectation may be that the jurisdiction will continue to allow that use to continue indefinitely. In that case what's probable in the market (market value) can be different than what a lender will accept (mortgage value).
How many times have we seen a lender require the 2nd stove and fridge to be removed before they'll do the loan? What does anyone think happens to that space after escrow closes? The stove and fridge get moved back out of the garage and back into that space, which then gets rented or otherwise occupied as the separate living space.peee