You need 3" clearance from the top of the tire to the wheelwell. If needed a small lift block can be used. I needed a 1" block on one of the TTs. cheap and easy to do. As far as limiting the payback, you seem to be conceeding that STs do fail more often. This is good. Recognizing a problem is halfway there to a solution. But financial payback is just a small part of it. Not having to deal with a torn up TT, and ruined trips are other forms of payback. How do you put a value on these? And finally IMO, (and the GOVT.testing standards,) there is no such thing as a quality ST tire.
They certainly are tested to lower standards and thats a fact. Not opinion. Another fun fact:It is illegal to put ST tires on automobiles, But perfectly legal to put LTs on trailers.There are reasons for this.(hint; lower testing standards for STs). Take a look at all the choices available for 16" LT tires. Most if not all brands have several price points and quality points to choose from. IE: Good, Better,Best. In ST tires each brand has ONE offering.