Not trying to be controversial, but why not just do it the right way and import the rv permanently paying the appropriate taxes?
Although SAT has the last word, as you know rules can be interpreted in different ways just as the issue with the heavy pickup or returning to the U.S. bringing what you think is passable or not. Each agent or department has its own criteria.
That said, the same can happen in Mexico with vehicles and paperwork in municipalities or at checkpoints. The Mexican aduana, in Laredo and Reynosa, have become very strict on vehicle importation and paperwork. There was a period a few years back when many agencias aduanales lost their licenses for doing crooked things and those that had their vehicles imported by them risked or still risk losing their vehicles.
Your plan just sounds like too much hassle. JMHO
