This can then be used as a negotiation chip in order to lower the price of the property.

And this one cracked me up: "We were sipping lukewarm coffee from chipped mugs, half convinced we’d made a mistake."

Nothing tiny (no legos!).

Now your a 62 yr young couple from Athens TX who recently retired and always dreamed of seeing London, Big Ben, having fish & chips, riding the "tube"..... 

Those are tiny, tiny obstacles compared to where this process succeeds or fails, and that is with the contracting. 

Plus the added requirements around getting drawings and general contractor for even adding a tiny closet.

If so, then they are not considered real property and you are dealing with the land value only.If they are stick built tiny homes on foundations, then that is something else.

.-- The carpet was nasty and walls unpainted and chipping.- The bathroom flooring was covered in mold and needed to be replaced.- The kitchen sink was unsecured and fell into the kitchen cabinet.- My insurance was cancelled until I fixed roof issues.- Debris littered the recently occupied unit, the basement, and all over the back yard.As mentioned, we had an initial video walk through before the contract to purchase.

Send them a pizza, crackers, and chips & salsa. 

If it is the same, there may be a tiny, marginal benefit* that is not worth the extra confusion.