Our 2018 28.5 RSTS has 16 inch tires, shackles in lower holes and I added the Morryde Correct Track to lift the trailer about 1.5-2 inches. I run with only 5 inches clearance from the bed on our 2015 Ram 2500 so have to be careful in unlevel areas. I welded in 2x3 steel crossmembers at the shackles to better handle the stress on the frame and shackles.
SeventyGTX I can assure you it is incorrect and unsafe to inflate tires to lower than the recommended cold temperature. Doing so creates a lot of stress and heat. Here is a link to tire engineer Roger Marble who often tries to correct peoples thinking in that regard:
"It is also important for people to understand that tires can tolerate a significant increase in pressure due to operation under load or at speed. While I can’t provide information on the specific design limits used by different tire companies, what I can say is that in my personal experience many new tires are capable of tolerating inflation increase of upwards of 100% or more over the number molded on the tire sidewall. So the idea that an undamaged tire will suddenly explode due to an increase in inflation due to operational heat is not justified."